function isEmail(vEMail)
{
	var regInvalid=/(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/;
	var regValid=/^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/;
	return (!regInvalid.test(vEMail)&&regValid.test(vEMail));
}
function check()
{
if (document.submitform.userName.value==""){
alert("联系人必须填写！");
document.submitform.userName.focus();
return false;
}
if (document.submitform.companyName.value==""){
alert("公司名称必须填写！");
document.submitform.companyName.focus();
return false;
}

if (document.submitform.tel.value==""){
alert("联系电话必须填写！");
document.submitform.tel.focus();
return false;
}

if (document.submitform.email.value==""){
alert("电子邮件必须填写！");
document.submitform.email.focus();
return false;
}
if (document.submitform.mailing_address.value==""){
alert("邮寄地址必须填写！");
document.submitform.mailing_address.focus();
return false;
}
if (document.submitform.productNo.value==""){
alert("产品编号必须填写！");
document.submitform.productNo.focus();
return false;
}

 document.submitform.submit();
}