function validate_email(inputvalue){	
      var pattern=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
      return pattern.test(inputvalue);
   }

   function newsletter_signup(){
          if(!validate_email($('#newsletter_email').val())){
            show_dialog("Please enter a valid email address","Newsletter Error")
          }else{
         	$.ajax({
         	   type: "get",
         	   url: "ajax_mailchimp.php?email="+$('#newsletter_email').val() ,
         	   dataType: "xml",
         	   error: function(msg){
         		   alert('error:'+msg.status+' : '+msg.statusText+' : '+msg.responseText,'Communications Error');
         		},
         	   success: function(xmlDocument){
                  var result = $('result',xmlDocument).text();
                  if(parseInt(result) == 1){
                     show_dialog("Thank you! Please check your email for your confirmation letter","Newsletter Signup Success!");
                  }else{
                     show_dialog("There was an error submitting your email address to the list:"+'<br /><em>'+$('errorMessage',xmlDocument).text()+'</em>',"Newsletter Error");
                  }
         	   }
            }); /* $.ajax */
          }
   }