function ajaxFunction(str){
    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)
          {      
          alert("Your browser does not support AJAX!");      
          return false;      
          }    
        }  
      }
    xmlHttp.onreadystatechange=function()
        {
        if(xmlHttp.readyState==4)
            {
            eval("var d=" + xmlHttp.responseText + ";");
            populateDropDown(document.Sickness.city,d);
            }
        }
    xmlHttp.open("GET","scripts/getcity.asp?str="+str,true);
    xmlHttp.send(null);
}

function populateDropDown(targetDropDown, optionsArray){

 //clear out any current options
 targetDropDown.options.length = 0;
 cityArray = optionsArray.split(",");

 //add new options using the values in the arraydr
 for (var i = 0; i < cityArray.length; i++) {
   //var newOption = document.createElement("OPTION");
   targetDropDown.options[i] = new Option(cityArray[i],cityArray[i]);
   //newOption.value = optionsArray[i];
   //newOption.innerText = optionsArray[i];
 }
 }