function changeit(ss)
{
 if (ss.style.display=="none")   {ss.style.display="";    
 } else  {ss.style.display="none";  } 
}   
function turnit(it)
{
  if(it == "pro1") {
		pro1.style.display="";pro2.style.display="none";
		bpro1.style.background="url(../Images/b_ena.gif)";
		bpro2.style.background="url(../Images/b_dis.gif)";
   } else {pro1.style.display="none"; pro2.style.display=""; 
		pro1.style.display="";pro2.style.display="none";
		bpro2.style.background="url(../Images/b_ena.gif)";
		bpro1.style.background="url(../Images/b_dis.gif)";
   }  
}   
function checkform(){
	if(email.frendname.value ==""){
		alert("请输入朋友名称");
		email.frendname.focus();
		return false;
	}else if(email.frendemail.value ==""){
		alert("请输入朋友电子邮件")
				email.frendemail.focus();
				return false;
	}else if(!(isEmail(email.frendemail.value))){
		alert("您输入的E-MAIL地址不正确，请重新输入")
				email.frendemail.focus();
				return false;
	}else if(email.youremail.value ==""){
		alert("请输入您的电子邮件")
				email.youremail.focus();
				return false;
	}else if(!(isEmail(email.youremail.value))){
		alert("您输入的E-MAIL地址不正确，请重新输入")
				email.youremail.focus();
				return false;
	}else if(email.subject.value ==""){
		alert("请输入主题")
				email.subject.focus();
				return false;
	}else if(email.con1.value =="" && email.con2.value =="" && email.con3.value =="" && email.con4.value ==""){
		alert("请输入内容")
				email.con1.focus();
				return false;
	} else {
		alert("功能正在建立中,请稍候");
		return false;
	}
return false;
}

function isEmail (s)
{   
    var i = 1;
    var sLength = s.length;
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}