几个常用的javascript

function valid_num(obj,max_integer,max_fraction,name,isfulfil) {
  if( typeof( window.blureerror) != 'undefined' && window.blureerror && window.bluetarget != obj ) return;
  var v = obj.value;
  if( !isfulfil && v == '') return;
  var str = "^[\\+]?[0-9]{1,"+max_integer+"}(\\.[0-9]{1,"+max_fraction+"})?$";
  var p = new RegExp( str);
  if (! p.test(v))
  {
  alert( "error input of "+name);
  window.blureerror = true;
  obj.style.background="pink";
  window.bluetarget = obj;
  obj.focus();
  return false;
  }
  return true;
 }

function reset_background(obj)
{
 obj.style.background="white";
 window.blureerror = false;
 window.bluetarget = '';
}

function valid_mail(obj)
{
 var v = obj.value;
 var p = /^([-_A-Za-z0-9\.]+)@([_A-Za-z0-9]+\.)+[A-Za-z0-9]{2,3}(,([-_A-Za-z0-9\.]+)@([_A-Za-z0-9]+\.)+[A-Za-z0-9]{2,3})*$/;
 if( ! p.test(v))
 {
  alert("Error format with maillist!");
  obj.focus();
  obj.style.background="pink";
  return false;
 }
 return true;
}


function do_back(url)
{
 var my_form = document.myform;
 my_form.action = url;
 my_form.submit();
}