function NewsletterPopup()
 {
 if(document.getElementById("txtEmail").value == "")
 {
 alert("You must enter your email address");
 window.focus();
 document.getElementById("txtEmail").focus();
 return;
 }
 if(new String(document.getElementById("txtEmail").value).indexOf("@") == -1)
 {
 alert("You must first enter a valid email address");
 window.focus();
 document.getElementById("txtEmail").focus();
 return;
 }
 if(new String(document.getElementById("txtEmail").value).indexOf(".") == -1)
 {
 alert("You must first enter a valid email address");
 window.focus();
 document.getElementById("txtEmail").focus();
 return;
 }
 window.open("subscribe.php?email=" + document.getElementById("txtEmail").value, null, "left=" + (screen.availWidth/2-225) + ",top=" + (screen.availHeight/2-150) + ",height=300,width=450,location=no,menubar=no,resizable=no,toolbar=no");
 }