js限制文本框只可以输入数字

封装了一下，要用的话直接调用下面getEvent函数即可

 

function getEvent() {
   if (document.all) {
      return window.event; //for ie
   }
   func = getEvent.caller;
   while (func != null) {
      var arg0 = func.arguments[0];
      if (arg0) {
        if ((arg0.constructor == Event || arg0.constructor == MouseEvent) || (typeof (arg0) == "object" && arg0.preventDefault && arg0.stopPropagation)) {
                 return arg0;
         }
      }
      func = func.caller;
   }
   return null;
 };
 
 function doit(){
     var ev = getEvent();
     if(ev.keyCode < 8) {return false;}
     else if(ev.keyCode > 8 && ev.keyCode < 48) {return false;}
     else if(ev.keyCode > 57 && ev.keyCode <96) {return false;}
     else if(ev.keyCode > 105) {return false;}
     else {return true;}
 };