diff --git a/lib/script.js b/lib/script.js
index a33a999..d884aee 100644
--- a/lib/script.js
+++ b/lib/script.js
@@ -4,22 +4,19 @@ var BufferReader = require('./encoding/bufferreader');
 var BufferWriter = require('./encoding/bufferwriter');
 var Opcode = require('./opcode');
 
-var Script = function Script(buf) {
-  if (!(this instanceof Script))
-    return new Script(buf);
-  
+var Script = function Script(from) {
+  if (!(this instanceof Script)) {
+    return new Script(from);
+  }
+
   this.chunks = [];
 
-  if (Buffer.isBuffer(buf)) {
-    this.fromBuffer(buf);
-  }
-  else if (typeof buf === 'string') {
-    var str = buf;
-    this.fromString(str);
-  }
-  else if (typeof buf !== 'undefined') {
-    var obj = buf;
-    this.set(obj);
+  if (Buffer.isBuffer(from)) {
+    this.fromBuffer(from);
+  } else if (typeof from === 'string') {
+    this.fromString(from);
+  } else if (typeof from !== 'undefined') {
+    this.set(from);
   }
 };
 
@@ -28,33 +25,26 @@ Script.prototype.set = function(obj) {
   return this;
 };
 
-Script.prototype.fromJSON = function(json) {
-  return this.fromString(json);
-};
-
-Script.prototype.toJSON = function() {
-  return this.toString();
-};
+Script.fromBuffer = function(buffer) {
+  var script = new Script();
+  script.chunks = [];
 
-Script.prototype.fromBuffer = function(buf) {
-  this.chunks = [];
-
-  var br = new BufferReader(buf);
+  var br = new BufferReader(buffer);
   while (!br.eof()) {
     var opcodenum = br.readUInt8();
 
     var len, buf;
     if (opcodenum > 0 && opcodenum < Opcode.map.OP_PUSHDATA1) {
       len = opcodenum;
-      this.chunks.push({
+      script.chunks.push({
         buf: br.read(len),
         len: len,
         opcodenum: opcodenum
       });
     } else if (opcodenum === Opcode.map.OP_PUSHDATA1) {
       len = br.readUInt8();
-      var buf = br.read(len);
-      this.chunks.push({
+      buf = br.read(len);
+      script.chunks.push({
         buf: buf,
         len: len,
         opcodenum: opcodenum
@@ -62,7 +52,7 @@ Script.prototype.fromBuffer = function(buf) {
     } else if (opcodenum === Opcode.map.OP_PUSHDATA2) {
       len = br.readUInt16LE();
       buf = br.read(len);
-      this.chunks.push({
+      script.chunks.push({
         buf: buf,
         len: len,
         opcodenum: opcodenum
@@ -70,17 +60,17 @@ Script.prototype.fromBuffer = function(buf) {
     } else if (opcodenum === Opcode.map.OP_PUSHDATA4) {
       len = br.readUInt32LE();
       buf = br.read(len);
-      this.chunks.push({
+      script.chunks.push({
         buf: buf,
         len: len,
         opcodenum: opcodenum
       });
     } else {
-      this.chunks.push(opcodenum);
+      script.chunks.push(opcodenum);
     }
   }
 
-  return this;
+  return script;
 };
 
 Script.prototype.toBuffer = function() {
@@ -88,24 +78,22 @@ Script.prototype.toBuffer = function() {
 
   for (var i = 0; i < this.chunks.length; i++) {
     var chunk = this.chunks[i];
+    var opcodenum;
     if (typeof chunk === 'number') {
-      var opcodenum = chunk;
+      opcodenum = chunk;
       bw.writeUInt8(opcodenum);
     } else {
-      var opcodenum = chunk.opcodenum;
+      opcodenum = chunk.opcodenum;
       bw.writeUInt8(chunk.opcodenum);
       if (opcodenum < Opcode.map.OP_PUSHDATA1) {
         bw.write(chunk.buf);
-      }
-      else if (opcodenum === Opcode.map.OP_PUSHDATA1) {
+      } else if (opcodenum === Opcode.map.OP_PUSHDATA1) {
         bw.writeUInt8(chunk.len);
         bw.write(chunk.buf);
-      }
-      else if (opcodenum === Opcode.map.OP_PUSHDATA2) {
+      } else if (opcodenum === Opcode.map.OP_PUSHDATA2) {
         bw.writeUInt16LE(chunk.len);
         bw.write(chunk.buf);
-      }
-      else if (opcodenum === Opcode.map.OP_PUSHDATA4) {
+      } else if (opcodenum === Opcode.map.OP_PUSHDATA4) {
         bw.writeUInt32LE(chunk.len);
         bw.write(chunk.buf);
       }
@@ -134,13 +122,13 @@ Script.prototype.fromString = function(str) {
           opcodenum: opcodenum
         });
         i = i + 2;
-      }
-      else {
+      } else {
         throw new Error('Invalid script');
       }
     } else if (opcodenum === Opcode.map.OP_PUSHDATA1 || opcodenum === Opcode.map.OP_PUSHDATA2 || opcodenum === Opcode.map.OP_PUSHDATA4) {
-      if (tokens[i + 2].slice(0, 2) != '0x')
+      if (tokens[i + 2].slice(0, 2) !== '0x') {
         throw new Error('Pushdata data must start with 0x');
+      }
       this.chunks.push({
         buf: new Buffer(tokens[i + 2].slice(2), 'hex'),
         len: parseInt(tokens[i + 1]),
@@ -156,19 +144,23 @@ Script.prototype.fromString = function(str) {
 };
 
 Script.prototype.toString = function() {
-  var str = "";
+  var str = '';
 
   for (var i = 0; i < this.chunks.length; i++) {
     var chunk = this.chunks[i];
+    var opcodenum;
     if (typeof chunk === 'number') {
-      var opcodenum = chunk;
-      str = str + Opcode(opcodenum).toString() + " ";
+      opcodenum = chunk;
+      str = str + Opcode(opcodenum).toString() + ' ';
     } else {
-      var opcodenum = chunk.opcodenum;
-      if (opcodenum === Opcode.map.OP_PUSHDATA1 || opcodenum === Opcode.map.OP_PUSHDATA2 || opcodenum === Opcode.map.OP_PUSHDATA4)
-        str = str + Opcode(opcodenum).toString() + " " ;
-      str = str + chunk.len + " " ;
-      str = str + "0x" + chunk.buf.toString('hex') + " ";
+      opcodenum = chunk.opcodenum;
+      if (opcodenum === Opcode.map.OP_PUSHDATA1 ||
+        opcodenum === Opcode.map.OP_PUSHDATA2 ||
+        opcodenum === Opcode.map.OP_PUSHDATA4) {
+        str = str + Opcode(opcodenum).toString() + ' ';
+      }
+      str = str + chunk.len + ' ';
+      str = str + '0x' + chunk.buf.toString('hex') + ' ';
     }
   }
 
@@ -176,14 +168,9 @@ Script.prototype.toString = function() {
 };
 
 Script.prototype.isOpReturn = function() {
-  if (this.chunks[0] === Opcode('OP_RETURN').toNumber()
-    &&
-    (this.chunks.length === 1
-    ||
-    (this.chunks.length === 2
-    && this.chunks[1].buf
-    && this.chunks[1].buf.length <= 40
-    && this.chunks[1].length === this.chunks.len))) {
+  if (this.chunks[0] === Opcode('OP_RETURN').toNumber() &&
+    (this.chunks.length === 1 ||
+      (this.chunks.length === 2 && this.chunks[1].buf && this.chunks[1].buf.length <= 40 && this.chunks[1].length === this.chunks.len))) {
     return true;
   } else {
     return false;
@@ -191,11 +178,7 @@ Script.prototype.isOpReturn = function() {
 };
 
 Script.prototype.isPublicKeyHashOut = function() {
-  if (this.chunks[0] === Opcode('OP_DUP').toNumber()
-    && this.chunks[1] === Opcode('OP_HASH160').toNumber()
-    && this.chunks[2].buf
-    && this.chunks[3] === Opcode('OP_EQUALVERIFY').toNumber()
-    && this.chunks[4] === Opcode('OP_CHECKSIG').toNumber()) {
+  if (this.chunks[0] === Opcode('OP_DUP').toNumber() && this.chunks[1] === Opcode('OP_HASH160').toNumber() && this.chunks[2].buf && this.chunks[3] === Opcode('OP_EQUALVERIFY').toNumber() && this.chunks[4] === Opcode('OP_CHECKSIG').toNumber()) {
     return true;
   } else {
     return false;
@@ -203,9 +186,7 @@ Script.prototype.isPublicKeyHashOut = function() {
 };
 
 Script.prototype.isPublicKeyHashIn = function() {
-  if (this.chunks.length === 2
-    && this.chunks[0].buf
-    && this.chunks[1].buf) {
+  if (this.chunks.length === 2 && this.chunks[0].buf && this.chunks[1].buf) {
     return true;
   } else {
     return false;
@@ -213,11 +194,7 @@ Script.prototype.isPublicKeyHashIn = function() {
 };
 
 Script.prototype.isScriptHashOut = function() {
-  if (this.chunks.length === 3
-    && this.chunks[0] === Opcode('OP_HASH160').toNumber()
-    && this.chunks[1].buf
-    && this.chunks[1].buf.length === 20
-    && this.chunks[2] === Opcode('OP_EQUAL').toNumber()) {
+  if (this.chunks.length === 3 && this.chunks[0] === Opcode('OP_HASH160').toNumber() && this.chunks[1].buf && this.chunks[1].buf.length === 20 && this.chunks[2] === Opcode('OP_EQUAL').toNumber()) {
     return true;
   } else {
     return false;
@@ -236,29 +213,35 @@ Script.prototype.isScriptHashIn = function() {
   }
 };
 
-Script.prototype.write = function(obj) {
-  if (typeof obj === 'string')
-    this.writeOp(obj);
-  else if (typeof obj === 'number')
-    this.writeOp(obj);
-  else if (Buffer.isBuffer(obj))
-    this.writeBuffer(obj);
-  else if (typeof obj === 'object')
+Script.prototype.add = function(obj) {
+  if (typeof obj === 'string') {
+    this._addOpcode(obj);
+  } else if (typeof obj === 'number') {
+    this._addOpcode(obj);
+  } else if (obj.constructor && obj.constructor.name && obj.constructor.name === 'Opcode') {
+    this._addOpcode(obj);
+  } else if (Buffer.isBuffer(obj)) {
+    this._addBuffer(obj);
+  } else if (typeof obj === 'object') {
     this.chunks.push(obj);
-  else
+  } else {
     throw new Error('Invalid script chunk');
+  }
   return this;
 };
 
-Script.prototype.writeOp = function(str) {
-  if (typeof str === 'number')
-    this.chunks.push(str);
-  else
-    this.chunks.push(Opcode(str).toNumber());
+Script.prototype._addOpcode = function(opcode) {
+  if (typeof opcode === 'number') {
+    this.chunks.push(opcode);
+  } else if (opcode.constructor && opcode.constructor.name && opcode.constructor.name === 'Opcode') {
+    this.chunks.push(opcode.toNumber());
+  } else {
+    this.chunks.push(Opcode(opcode).toNumber());
+  }
   return this;
 };
 
-Script.prototype.writeBuffer = function(buf) {
+Script.prototype._addBuffer = function(buf) {
   var opcodenum;
   var len = buf.length;
   if (buf.length > 0 && buf.length < Opcode.map.OP_PUSHDATA1) {
@@ -270,7 +253,7 @@ Script.prototype.writeBuffer = function(buf) {
   } else if (buf.length < Math.pow(2, 32)) {
     opcodenum = Opcode.map.OP_PUSHDATA4;
   } else {
-    throw new Error("You can't push that much data");
+    throw new Error('You can\'t push that much data');
   }
   this.chunks.push({
     buf: buf,