How do you check Request.Form("field") for blanks using vbScript?

It's easy to do with JavaScript.
In the header you place the functions
function isBlank(strObject) {
 var re = /\S+/;
   if (!strObject) return true;
   if (re.test(strObject.value)) return false;
   else return true;
}
And then
If (isBlank(Request.QueryString("field")){
  Do this;
}

<%
If (Request("field") = "") Then
    ' field is blank
End If
%>

This is a confusing question...

Do you mean vbScript in the client or on the server? Mentioning JavaScript kind of confuses the question.