function getCenter(w,h){
	var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
	var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
	var width = document.documentElement.clientWidth || document.body.clientWidth;
	var height = document.documentElement.clientHeight || document.body.clientHeight;
	return {left : Math.round((width + scrollX - w)/2) + "px", top : Math.round((height + scrollY - h)/2) + "px"};
}

// Showing Sajax Status
AST_load = "à?àÀàÃá?á?àÇàÊàÀ...";
AST_save = "Saving...";
AST_clear = "";

function setAjaxStatus(str) {
    if (document.getElementById("ajaxStatus")) {
        var div = document.getElementById("ajaxStatus");
    } else {
        var div  = document.createElement("DIV");
        div.className = "ajaxStatus";
        div.id = "ajaxStatus";
        div.setAttribute("id", "ajaxStatus");
        document.body.appendChild(div);
    }
    div.innerHTML = str;
    if (str == AST_clear) {
        div.style.visibility = "hidden";
        return;
    }
    
    var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
    var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
    var width = document.documentElement.clientWidth || document.body.clientWidth;
    
    div.style.left = width - div.clientWidth + scrollX +"px";
    div.style.top = scrollY+"px";
    div.style.visibility = "visible";
}