var g_UI_size = 11;
var g_UI_index = 0;

function changeUI(value){
	size = parseInt(eval(g_UI_index + parseInt(value)))
//	alert("Current UI index : " + g_UI_index);	
//	alert("New size index : " + size);
	var defaultFontSize = 11;
	var unitOfMeasure = "px";
	var increaseSizeBy = 2;
	var validChange = false;
	//increase/decrease font size for this page
	switch(size){
		case 0:	g_UI_index = size
				g_UI_size = defaultFontSize
				newSize = g_UI_size + unitOfMeasure // set to default 				
				validChange = true;
				break;
		case 1:	g_UI_index = size
				g_UI_size = parseInt(eval(defaultFontSize + increaseSizeBy))
				newSize = g_UI_size + unitOfMeasure // set to default 				
				validChange = true;
				break;
		case 2:	g_UI_index = size
				g_UI_size = parseInt(eval(defaultFontSize + (increaseSizeBy * 2)))
				newSize = g_UI_size + unitOfMeasure // set to default 							
				validChange = true;
				break;
		default: break;
	}

//	alert("New g_UI_size is now : " + g_UI_size + " with an index of : " + g_UI_index);	

	if(validChange){
//		alert("Setting main_content to : " + newSize);	
		content = document.getElementById('main_content')
		content.style.fontSize = newSize
	
		// Save UI size
		// create xmlHTTP
		if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
			xmlhttp=new XMLHttpRequest();
		}else{// code for IE6, IE5
			xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
		xmlhttp.onreadystatechange=function(){
			if (xmlhttp.readyState==4 && xmlhttp.status==200){
				document.getElementById("server_response").innerHTML=xmlhttp.responseText;
//				document.getElementById("server_response").innerHTML="onreadystatechange function is called";
			}
		}
		
		//send font size change - sets cookie value
		params = "ui_level=" + g_UI_index
		xmlhttp.open("GET","/Scripts/updateUIsettings.php?" + params, true);
		xmlhttp.send();
		
	}
	
}