function defaul_home()
{
	this.home.style.behavior='url(#default#homepage)';this.home.setHomePage('http://www.doyougo.com/');
}
function is_ok(str)
	{
		exp=/[^0-9a-zA-Z_]/g;
		if(str.search(exp) != -1)
		{
			return false;
		}
		return true;
	}
function checkform()
	{
		
		if( TheForm.user_name.value =="" ) {
	                alert("\请输入多友国通行证用户名!")
									TheForm.user_name.select();
									TheForm.user_name.focus();
	                return false;
	       }
	   
	   if(!is_ok(TheForm.user_name.value)) {
	                alert("\请输入合法的多友国通行证用户名!")
									TheForm.user_name.select();
									TheForm.user_name.focus();
	                return false;
	       }
	   if( (TheForm.user_name.value.length>12)||(TheForm.user_name.value.length<3) ) {
	                alert("\多友国通行证用户名必须在3到12个字符之间!")
									TheForm.user_name.select();
									TheForm.user_name.focus();
	                return false;
	       }

	if((TheForm.password.value =="")||(TheForm.password.value.length>20)||(TheForm.password.value.length<6) )
	{
		alert("\请正确输入密码，密码必须在6到20个字符之间 !!")
		TheForm.password.select();
		TheForm.password.focus();
		return false;
	}

	   
//	    return true;
    TheForm.submit();
	}