How to return response from webservice
<p>I have made a web service and clients will call its methods. Suppose one method takes four parameters and I want to check that if any one of these is empty I want to send a response back to the client and I want to send it like an alert so client knows what argument is empty. I can not force client to give all parameters accurate. Is this possible?</p>

<pre><code>[WebMethod]
Public void Method1(string str1,string str2,string str3,string str4)
{
    if((str1=="") || (str2==""))
    {
        //send response back to client in form of an alert
    }
}
</code></pre>
