var easychange = function(foochange){ 
     if(!foochange||foochange.constructor!=Function){return;} 
     try{this.watch("value",function(id,oldval,newval){foochange(newval);return newval;});}catch(e){} 
     this.setAttribute('oninput','('+foochange.toString()+')(this.value)'); 
     this.onpropertychange = function(){foochange(this.value);}; 
     this.onmousemove = function(){foochange(this.value);}; 
     this.onkeyup = function(){foochange(this.value);}; 
 }; 
 

var dx = document.getElementById('x');
easychange.call(dx,function(newvalue){document.title = newvalue;});

var dx = document.getElementById('x');

easychange.call(dx,(function(){return function(newvalue){dx.value="xxxx"+dx.value}})(dx));

------解决方案--------------------
支持，谢谢~~

------解决方案--------------------
或者

easychange.call(o,(function(){return function(newvalue){o.value="name:"+newvalue}})(o));