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;}
  };