兼容IE 和火狐

//验证只能输入数字和Backspace键
function kpress(event){
  alert(222);
 var e = event ? event : (window.event ? window.event :null);
 var k=e.keyCode ? e.keyCode : e.which; //兼容火狐的获取按键ASCII码方式
 if(k >= 48 && k <= 57 || k == 8 || k == 9){
  return true;
 }
 return false;
}