var xmlHttp

//START FUNCTION TO GET DRIVING DIRECTIONS
function getDrivingDirections(str)
{ 
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
 {
 alert ("Browser does not support HTTP Request")
 return
 }
var url="trail_info_driving_directions.php?action=show&str="+str+"&sid="+Math.random()
xmlHttp.onreadystatechange=showGetDirections 
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
}
//END FUCTION TO GET DRIVING DIRECTIONS


//START FUNCTION TO HIDE DRIVING DIRECTIONS
function hideDrivingDirections(str)
{ 
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
 {
 alert ("Browser does not support HTTP Request")
 return
 }
var url="trail_info_driving_directions.php?action=hide&str="+str+"&sid="+Math.random()
xmlHttp.onreadystatechange=getDirections 
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
}
//END FUCTION TO HIDE DRIVING DIRECTIONS

//START FUNCTION TO CHANGE STARTING LOCATION
function changeDrivingDirections(str)
{ 
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
 {
 alert ("Browser does not support HTTP Request")
 return
 }
var url="trail_info_driving_directions.php?action=change&str="+str+"&sid="+Math.random()
xmlHttp.onreadystatechange=getDirections 
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
}
//END FUCTION TO CHANGE STARTING LOCATION


//THIS FUNCTION FOR THE SHOW DRIVING DIRECTIONS RESPONSE
function showGetDirections() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 { 
 document.getElementById("drivingDirections").innerHTML=xmlHttp.responseText 
 drivingDirections()
 } 
}
//END FUNCTION FOR THE GET DRIVING DIRECTIONS RESPONSE


//THIS FUNCTION FOR THE HIDE AND CHANGE DRIVING DIRECTIONS RESPONSE
function getDirections() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 { 
 document.getElementById("drivingDirections").innerHTML=xmlHttp.responseText 
 } 
}
//END FUNCTION FOR THE GET DRIVING DIRECTIONS RESPONSE


//CHECK BROWSER COMPATIBILITY WITH AJAX
function GetXmlHttpObject()
{
var xmlHttp=null;
try
 {
 // Firefox, Opera 8.0+, Safari
 xmlHttp=new XMLHttpRequest();
 }
catch (e)
 {
 //Internet Explorer
 try
  {
  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  }
 catch (e)
  {
  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
return xmlHttp;
} 
//END BROWSER COMPATIBILITY CHECK