function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

var http = createRequestObject();

function getSizes(tvmake) {
	
	var url = "front_queries.php";
	var data = "action=get_sizes&tvmake=" + tvmake.value;
	http.open("POST", url, true);
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http.send(data);
	http.onreadystatechange = handleDropResponse;

}

function handleResponse() {

    if(http.readyState == 4){
        var response = http.responseText;
		var layers_replace = new Array();
		
		    layers_replace = response.split('*');	
			
			for(i=0;i<layers_replace.length;i++) {
					var update = new Array();
					update = layers_replace[i].split('|');
					document.getElementById(update[0]).innerHTML = update[1];
			}
    }
}

function handleDropResponse() {
  if (http.readyState == 4) {
    if (http.responseText.indexOf('invalid') == -1) {
      qresults = http.responseText.split(",");
	  
		  var selbox = document.forms.form1.screensize;
     	  selbox.options.length = 0;	  
			for (var i=0;i<qresults.length;i++)
			{
		      details = qresults[i].split("^");
			  selbox.options[selbox.options.length] = new Option(details[0],details[1]);		      
			}

    }
  }
}