function check()
{
    var check;    
    if (document.all.username.value=="")
    { alert("帐号不能为空。");
    document.all.username.focus();
    return false;
    exit; }				            
    if (!voidNum(document.all.password.value))
    { alert("密码不能为空。");
    document.all.password.focus();
    return false;
    exit; }
    location.href="/passport/usercheck.aspx?username="+document.all.username.value+"&password="+document.all.password.value;
}
 function voidNum(argValue) 
 {
  var flag1=false;
  var compStr="1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMN.OPQRSTUVWXYZ_-";
  var length2=argValue.length;
  for (var iIndex=0;iIndex<length2;iIndex++)
  	{
		var temp1=compStr.indexOf(argValue.charAt(iIndex));
		if(temp1==-1) 
		{
			flag1=false;
			break;							
		}
		else
		{flag1=true;}
	}
	return flag1;
 }