if (!Function.prototype.bind) { 
Function.prototype.bind = (function (){ 
var slice = Array.prototype.slice; 
return function (thisArg){ 
var target = this, boundArgs = slice.call(arguments, 1); 
if (typeof target !== 'function') { 
throw new TypeError()
} 
function bound(){ 
var args = boundArgs.concat(slice.call(arguments)); 
target.apply(this instanceof bound? this: thisArg, args); 
} 
bound.prototype = (function F(proto){ 
if (proto) { 
F.prototype = proto; 
} 
if (!(this instanceof F)) { 
return new F(); 
} 
} 
)(target.prototype); 
return bound; 
} 
; 
} 
)(); 
}