function formCheck(objform)
  {
   with(objform){
	if ( objform.userid.value == "" || objform.userid.value == "null" || objform.userid.value == null || objform.userid.value == "undefined" )
	{
		alert("用户名不可以为空");
		objform.userid.focus();
        return false;
	}
	if ( objform.passcode.value == "" || objform.passcode.value == "null" || objform.passcode.value == null || objform.passcode.value == "undefined" )
	{
		alert("密码不可以为空");
		objform.passcode.focus();
        return false;
	}
	if ( objform.image.value == "" || objform.image.value == "null" || objform.image.value == null || objform.image.value == "undefined" )
	{
		alert("请输入验证码");
		objform.image.focus();
        return false;
	}
	if ( objform.url.value == "" || objform.url.value == "null" || objform.url.value == null || objform.url.value == "undefined" )
	{
		//alert(location);
		objform.url.value=location;
	}
   }
	return true;
  }
  
/*
	unipro_clearCookie(name)
	参数:name
			name为欲清空cookie的名字
	功能:清除名字为name的cookie
*/
function unipro_clearCookie(name ) {
	document.cookie=name+"=; " + "domain=sina.com.cn; path=/; ";     
	//bites = document.cookie.split("; ");
} 

/*
	unipro_UniProLogout()
	功能:安全退出时清除COOKIE
*/
function unipro_UniProLogout() {
	unipro_clearCookie("SINAPRO");
	unipro_clearCookie("SINA-AVATAR");
	unipro_clearCookie("SINAPROC");
	unipro_clearCookie("nick");
	unipro_clearCookie("SINA_NU");      
	unipro_clearCookie("SINA_OU");
	unipro_clearCookie("appmask");
	unipro_clearCookie("gender");
	unipro_clearCookie("UNIPROTM");
	unipro_clearCookie("UNIPROU");
	unipro_clearCookie("SINA_USER");
	unipro_clearCookie("SMS_COOKIE");
	unipro_clearCookie("SID");
	unipro_clearCookie("PAYSID");
	unipro_clearCookie("UNIPROM");
	return true;
}