// JavaScript Document
function chArt(dvalue)
{
	if(dvalue == 1){
		art1.background = "images/on.jpg";
		hrart1.style.display = '';
		art2.background = "images/out.jpg";
		hrart2.style.display = 'none';
		art3.background = "images/out.jpg";
		hrart3.style.display = 'none';

	}
	else if(dvalue == 2){
		art1.background = "images/out.jpg";
		hrart1.style.display = 'none';
		art2.background = "images/on.jpg";
		hrart2.style.display = '';
		art3.background = "images/out.jpg";
		hrart3.style.display = 'none';
	}
	else if(dvalue == 3){
	art1.background = "images/out.jpg";
	hrart1.style.display = 'none';
	art2.background = "images/out.jpg";
	hrart2.style.display = 'none';
	art3.background = "images/on.jpg";
	hrart3.style.display = '';

	}
}

function CheckForm()
{
	uid = del_space(document.myform.username.value);
	if (uid.length == 0)
	{
		alert("请输入登陆帐号!");
		document.myform.username.focus();
		return false;
	} 
	if(checkerr(uid) == "1"){
		alert("登陆帐号由a～z的英文字母(不区分大小写)、0～9的数字、点、减号或下划线组成，长度为3～18个字符，只能以数字或字母开头和结尾!");
		document.myform.username.focus();
		return false;
	}
	
	if (uid.length < 3)
	{
		alert("登陆帐号不能小于3个字符!");
		document.myform.username.focus();
		return false;
	}
	
	if (uid.length > 18)
	{
		alert("登陆帐号不能超过18个字符!");
		document.myform.username.focus();
		return false;
	}
  
	var pwd = document.myform.password.value;
	if (pwd=="")
	{
		alert("请输入登录密码！");
		myform.password.focus();		
		return (false);
	}
	if (pwd.length < 6)
	{
		alert("密码不能少于六位！");
		myform.password.focus();
		return false;   
	}
	if (pwd.length > 16) 
	{
		alert("密码不能大于十六位！");
		myform.password.focus();
		return false;
	}
	return true;  
}

function checkerr(string)
{
	var i=0;
	for (i=0; i<string.length; i++)
	{
		if((string.charAt(i) < '0' || string.charAt(i) > '9') && (string.charAt(i) < 'a' || string.charAt(i) > 'z')&& (string.charAt(i)!='-')&& (string.charAt(i)!='_')&& (string.charAt(i)!='.')) 
		{
			return 1;
		}
	}
	return 0;//pass
}

function del_space(s)
{
	for(i=0;i<s.length;++i)
	{
	 if(s.charAt(i)!=" ")
		break;
	}

	for(j=s.length-1;j>=0;--j)
	{
	 if(s.charAt(j)!=" ")
		break;
	}

	return s.substring(i,++j);
}