function checkform(){
if(form1.keyword.value=="")
    {alert("请填写关键字!");
	 form1.keyword.focus();
	 return false;
	}
else if(form1.searchtype.value=="")
    {alert("请选择类别!");
	 form1.searchtype.focus();
	 return false;
	}
	else
	  return true;
}
 
 function checkform1(){
if(form.keyword.value=="")
    {alert("请填写关键字!");
	 form.keyword.focus();
	 return false;
	}
else if(form.searchtype.value=="")
    {alert("请选择类别!");
	 form.searchtype.focus();
	 return false;
	}
	else
	  return true;
}
 
  function checkform2(){
 var str1 = document.form2.email.value
    if(str1.indexOf("@") == -1 || str1.indexOf(".") == -1)
	{ 
	alert("联系邮箱格式不正确,请重新填写！"); 
	document.form2.email.focus();
	document.form2.email.select();
	return false; 
	}

if(form2.name.value=="")
    {alert("请输入您的姓名!");
	 form2.name.focus();
	 return false;
	}
else if(form2.content.value=="")
    {alert("请输入您的评论内容!");
	 form2.content.focus();
	 return false;
	}
else if(form2.email.value=="")
    {alert("请输入您的Email!");
	 form2.email.focus();
	 return false;
	}
else if(form2.code.value=="")
    {alert("请输入验证码!");
	 form2.code.focus();
	 return false;
	}
else if(form2.code.value.length<4)
    {alert("请输入正确的验证码!");
	 form2.code.focus();
	 return false;
	}
else if(form2.code.value.length>4)
    {alert("请输入正确的验证码!");
	 form2.code.focus();
	 return false;
	}
	else
	  return true;
}
 
 
   function checkform3(){
	    var str1 = document.form3.email.value
    if(str1.indexOf("@") == -1 || str1.indexOf(".") == -1)
	{ 
	alert("联系邮箱格式不正确,请重新填写！"); 
	document.form3.email.focus();
	document.form3.email.select();
	return false; 
	}

if(form3.contact.value=="")
    {alert("请输入联系人!");
	 form3.contact.focus();
	 return false;
	}
else if(form3.company.value=="")
    {alert("请输入您的公司名称!");
	 form3.company.focus();
	 return false;
	}
else if(form3.add.value=="")
    {alert("请输入您的地址!");
	 form3.add.focus();
	 return false;
	}else if(form3.post.value=="")
    {alert("请输入您的邮编!");
	 form3.post.focus();
	 return false;
	}

else if(form3.tel.value=="")
    {alert("请输入您的电话!");
	 form3.tel.focus();
	 return false;
	}
else if(form3.email.value=="")
    {alert("请输入您的电子邮件!");
	 form3.email.focus();
	 return false;
	}
	else if(form3.code.value.length<4)
    {alert("请输入正确的验证码!");
	 form3.code.focus();
	 return false;
	}
else if(form3.code.value.length>4)
    {alert("请输入正确的验证码!");
	 form3.code.focus();
	 return false;
	}

else if(form3.content.value.length<10)
    {alert("请输入意见建议!");
	 form3.content.focus();
	 return false;
	}
	else
	  return true;
}
 
 
   function checkform4()
{
var check=true;
for (var i=0;i<document.form4.usertype.length;i++)
{
	if (document.form4.usertype[i].checked)
	 {
	 		 check=false;
		break;

	 }
}
         if (check)
		{
          alert("请选择留言身份！");
          document.form4.usertype[1].focus();
          return (false);
       } 
	   
if (document.form4.usertype[0].checked)	 
{
if(form4.username.value=="")
    {alert("请输入用户名!");
	 form4.username.focus();
	 return false;
	}
if(form4.password.value=="")
    {alert("请输入密码!");
	 form4.password.focus();
	 return false;
	}
if(form4.title.value=="")
    {alert("请输入标题!");
	 form4.title.focus();
	 return false;
	}
	if(form4.MessageContent.value=="")
    {alert("请输入您想询问的详细信息!");
	 form4.MessageContent.focus();
	 return false;
	}
	if(form4.code.value.length<4)
    {alert("请输入正确的验证码!");
	 form4.code.focus();
	 return false;
	}
	if(form4.code.value.length>4)
    {alert("请输入正确的验证码!");
	 form4.code.focus();
	 return false;
	}
   }	
if (document.form4.usertype[1].checked)	 
{
	if(form4.title.value=="")
    {alert("请输入标题!");
	 form4.title.focus();
	 return false;
	}
	if(form4.MessageContent.value=="")
    {alert("请输入您想询问的详细信息!");
	 form4.MessageContent.focus();
	 return false;
	}
	
 var str1 = document.form4.email.value
    if(str1.indexOf("@") == -1 || str1.indexOf(".") == -1)
	{ 
	alert("联系邮箱格式不正确,请重新填写！"); 
	document.form4.email.focus();
	document.form4.email.select();
	return false; 
	}
 if(form4.contact.value=="")
    {alert("请输入联系人!");
	 form4.contact.focus();
	 return false;
	}
else if(form4.company.value=="")
    {alert("请输入您的公司名称!");
	 form4.company.focus();
	 return false;
	}
else if(form4.email.value=="")
    {alert("请输入您的电子邮件!");
	 form4.email.focus();
	 return false;
	}
else if(form4.tel.value=="")
    {alert("请输入您的电话!");
	 form4.tel.focus();
	 return false;
	}
else if(form4.add.value=="")
    {alert("请输入您的地址!");
	 form4.add.focus();
	 return false;
	}
else if(form4.post.value=="")
    {alert("请输入您的邮编!");
	 form4.post.focus();
	 return false;
	}
 	else if(form4.code.value.length<4)
    {alert("请输入正确的验证码!");
	 form4.code.focus();
	 return false;
	}
else if(form4.code.value.length>4)
    {alert("请输入正确的验证码!");
	 form4.code.focus();
	 return false;
	}
}
	else
	  return true;
}