var http_request = false;
   function makePOSTRequest(url, parameters) {
      http_request = false;
      if (window.XMLHttpRequest) { // Mozilla, Safari,...
         http_request = new XMLHttpRequest();
         if (http_request.overrideMimeType) {
            http_request.overrideMimeType('text/xml');
         }
      } else if (window.ActiveXObject) { // IE
         try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
         } catch (e) {
            try {
               http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
         }
      }
      if (!http_request) {
         alert('Cannot create XMLHTTP instance');
         return false;
      }

      http_request.onreadystatechange = alertContents;
      http_request.open('POST', url, true);
      http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
      http_request.setRequestHeader("Content-length", parameters.length);
      http_request.setRequestHeader("Connection", "close");
      http_request.send(parameters);
   }

   function alertContents() {
      if (http_request.readyState == 4) {
         if (http_request.status == 200) {
            //alert(http_request.responseText);
            result = http_request.responseText;
            document.getElementById('zoekresultaten').innerHTML = result;
         } else {
            alert('There was a problem with the request.');
         }
      }
   }

   function get(obj) {
      var poststr = "zoeken_naam=" + encodeURI( document.getElementById("zoeken_naam").value ) +
                    "&zoeken_alternatief=" + encodeURI( document.getElementById("zoeken_alternatief").value );

		if (document.getElementById("zoeken_windows").checked) {
			poststr += "&zoeken_windows=1";
		} else {
			poststr += "&zoeken_windows=0";
		}
		if (document.getElementById("zoeken_macosx").checked) {
			poststr += "&zoeken_macosx=1";
		} else {
			poststr += "&zoeken_macosx=0";
		}
		if (document.getElementById("zoeken_linux").checked) {
			poststr += "&zoeken_linux=1";
		} else {
			poststr += "&zoeken_linux=0";
		}
		if (document.getElementById("zoeken_64bit").checked) {
			poststr += "&zoeken_64bit=1";
		} else {
			poststr += "&zoeken_64bit=0";
		}
		if (document.getElementById("zoeken_nederlands").checked) {
			poststr += "&zoeken_nederlands=1";
		} else {
			poststr += "&zoeken_nederlands=0";
		}
		if (document.getElementById("audio").checked) {
			poststr += "&audio=1";
		} else {
			poststr += "&audio=0";
		}
		if (document.getElementById("beveiliging").checked) {
			poststr += "&beveiliging=1";
		} else {
			poststr += "&beveiliging=0";
		}
		if (document.getElementById("grafisch").checked) {
			poststr += "&grafisch=1";
		} else {
			poststr += "&grafisch=0";
		}
		if (document.getElementById("hulpmiddelen").checked) {
			poststr += "&hulpmiddelen=1";
		} else {
			poststr += "&hulpmiddelen=0";
		}
		if (document.getElementById("internet").checked) {
			poststr += "&internet=1";
		} else {
			poststr += "&internet=0";
		}
		if (document.getElementById("kantoor").checked) {
			poststr += "&kantoor=1";
		} else {
			poststr += "&kantoor=0";
		}
		if (document.getElementById("ontwikkeling").checked) {
			poststr += "&ontwikkeling=1";
		} else {
			poststr += "&ontwikkeling=0";
		}
		if (document.getElementById("video").checked) {
			poststr += "&video=1";
		} else {
			poststr += "&video=0";
		}
		if (document.getElementById("vrije_software").checked) {
			poststr += "&vrije_software=1";
		} else {
			poststr += "&vrije_software=0";
		}
		if (document.getElementById("freeware").checked) {
			poststr += "&freeware=1";
		} else {
			poststr += "&freeware=0";
		}
		if (document.getElementById("shareware").checked) {
			poststr += "&shareware=1";
		} else {
			poststr += "&shareware=0";
		}
		
      makePOSTRequest('zoeken_resultaat.php', poststr);
   }