function sub_form() 
  { 
  var xmlHttp; 
  try 
    { 
    // Firefox, Opera 8.0+, Safari 
    xmlHttp=new XMLHttpRequest(); 
    } 
  catch (e) 
    { 
    // Internet Explorer 
    try 
      { 
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); 
      } 
    catch (e) 
      { 
      try 
        { 
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); 
        } 
      catch (e) 
        { // no js enabled in browser
        alert("Your browser does not support AJAX!"); 
        return false; 
        } 
      } 
    }
    // end of standard code 
    xmlHttp.onreadystatechange=function() 
          { 
          if(xmlHttp.readyState==4)// readystate 
          { 
          //request done  
              if(xmlHttp.responseText==1)// no errors show thankyou msg.
              {
              document.getElementById('ct_ct').innerHTML="<h1>thank you, we'll contact you shortly</h1>";
              }
              else if (xmlHttp.responseText==2)// fields empty
              {
              document.getElementById('msg').innerHTML="check required fields";
			  document.getElementById('f_name').className="fld req";
			  document.getElementById('email').className="fld req";
              }
              else if (xmlHttp.responseText==3)// error send email
              {
              document.getElementById('msg').innerHTML="error processing your reqest!";
              }          
              else if (xmlHttp.responseText==5)// invalid email address
              {
              document.getElementById('msg').innerHTML="you entered an invalid email address!";
			  document.getElementById('f_name').className="fld";
			  document.getElementById('l_name').className="fld";
			  document.getElementById('email').className="fld req";
              }

		 }
          else  
         { 
         // request still pending
     	document.getElementById('msg').innerHTML='processing...' 
         } 
 
      }

    xmlHttp.open("GET","process.php?f_name=" + document.getElementById('f_name').value +
	"&l_name=" + document.getElementById('l_name').value + 
	"&company=" + document.getElementById('company').value + 
	"&phone=" + document.getElementById('phone').value + 
	"&asi=" + document.getElementById('asi').value + 
	"&email=" + document.getElementById('email').value + 
	"&txt_msg=" + document.getElementById('txt_msg').value,true); 
    xmlHttp.send(null); 
  }