function ajaxFunction() {
	
		var ajaxRequest = false;
		try {
			//Firefox, Opera, Safari
			ajaxRequest=new XMLHttpRequest();
		}
			catch(e)
			{
				try {
					//IE
					ajaxRequest=new ActiveXObject("Msxml2.XMLHTTP");
				}
					catch(e)
					{
						try{
						ajaxRequest=new ActiveXObject("Microsoft.XMLHTTP");
						}
					catch(e)
					{
						alert("Your browser does not support AJAX!");
						return false;
					}
					}
			}
			
			//receive data sent from server
			ajaxRequest.onreadystatechange = function(){
				if(ajaxRequest.readyState == 4){
					
					var ajaxDisplay = document.getElementById('trail_results');
					ajaxDisplay.innerHTML = ajaxRequest.responseText;
					
				}
			}
			
			//EVENT TYPE
			var form = document.forms["trails_form"];
			var all_amenities = 0;			
			var paved = 0;
			var dirt = 0;
			var view = 0;
			var ada = 0;
			var city_park = 0;
			var trailhead = 0;
			var head = 0;
			var parking = 0;
			var restroom = 0;
			var water = 0;
			var shade = 0;
			var picnic = 0;
			var info = 0;
			var searched_for = '';
			
			if(form.all_amenities.checked){ all_amenities = 1; }
			
			if(form.paved.checked){ paved = 1; searched_for += "Paved Surface, "; }
			if(form.dirt.checked){ dirt = 1; searched_for += "Natural Surface, "; }
			if(form.view.checked){ view = 1; searched_for += "Scenic Views, "; }
			if(form.ada.checked){ ada = 1; searched_for += "ADA Accessible, "; }
			if(form.city_park.checked){ city_park = 1; searched_for += "City Park on Route, "; }
			if(form.trailhead.checked){ trailhead = 1; searched_for += "Trailhead Access, "; }
			if(form.head.checked){ head = 1; searched_for += "Trailhead Location, "; }
			if(form.parking.checked){ parking = 1; searched_for += "Designated Parking, "; }
			if(form.restroom.checked){ restroom = 1; searched_for += "Restroom Facilities, "; }
			if(form.water.checked){ water = 1; searched_for += "Drinking Fountain, "; }
			if(form.shade.checked){ shade = 1; searched_for += "Shade / Shelter, "; }
			if(form.picnic.checked){ picnic = 1; searched_for += "Picnic Facilities, "; }
			if(form.info.checked){ info = 1; searched_for += "Information Kiosk, "; }
						
			ajaxRequest.open("GET", "get_trails.php?c=" + new Date().getTime() + "&all_amenities=" + all_amenities + "&paved=" + paved + "&dirt=" + dirt + "&view=" + view + "&ada=" + ada + "&city_park=" + city_park + "&trailhead=" + trailhead + "&head=" + head + "&parking=" + parking + "&restroom=" + restroom + "&water=" + water + "&shade=" + shade + "&picnic=" + picnic + "&info=" + info + "&searched_for= " + searched_for, true);
			ajaxRequest.send(null);
	
	}//end ajaxFunction