function ltrim(s, c)
{
	if (!c)
		c = ' ';
	var i;
	i=0;
	var n;
	n = s.length;
	while((i<n)&&(s.charAt(i)==c)) i++;
		s = s.substring(i);
	return(s);
} 

function rtrim(s, c)
{
	if (!c)
		c = ' ';
	var n;
	n = s.length;
	var i;
	i = s.length-1;
	while((i>=0)&&(s.charAt(i)==c)) i--;
		s = s.substring(0,i+1);
	return(s);
}

function trim(s, c)
{
	if (!c)
		c = ' ';
	s = ltrim(s, c);
	s = rtrim(s, c);
	return(s);
}

function gsgRegExp(email, reg)
{
	value = email;
	if (value.length == 0)
		return false;
	var rx = new RegExp(reg);
	var matches = rx.exec(value);
    return (matches != null && value == matches[0]);
}


function isEmail(email)
{
	if (email.length<=0)
		return false;
	if  (!gsgRegExp(email, "\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*"))
	{
		return false;
	}
	return true;
}

function gsgGetCheckboxValues(chkName) {
	var eleArr = document.getElementsByName(chkName);
	eleCount = eleArr.length;
	eleVals = "";
	for (eleIdx=0; eleIdx<eleCount; eleIdx++) {
		if (eleArr[eleIdx].checked) {
			eleVals = eleVals + "," + eleArr[eleIdx].value;
		}
	}
	eleVals = trim(eleVals, ",");
	return eleVals;
}

function gsgSetContent(divID, strContent) {
	if (document.getElementById(divID))
		document.getElementById(divID).innerHTML = strContent;
}

var arr_obj = new Array();
for (gsgIdx=0; gsgIdx<10; ++gsgIdx)
	arr_obj[gsgIdx] = false;

function gsgLoadContent(urlContent, divID, idx) {
	arr_obj[idx] = false;
	
	if (window.XMLHttpRequest) 
		arr_obj[idx] = new XMLHttpRequest();
	else 			
		arr_obj[idx] = new ActiveXObject("Microsoft.XMLHTTP");
	if (arr_obj[idx])
	{
		arr_obj[idx].onreadystatechange = function()
		{
			if (arr_obj[idx].readyState == 0) { }
			if (arr_obj[idx].readyState == 1) { }
			if (arr_obj[idx].readyState == 2) { }
			if (arr_obj[idx].readyState == 3) { }
			if (arr_obj[idx].readyState == 4 && arr_obj[idx].status == 200)
			{
				gsgSetContent(divID, arr_obj[idx].responseText);
			}
		}
		urlContent = rtrim(urlContent, '?');
		if (urlContent.indexOf("?")==-1)
			urlContent = urlContent + "?";
		else
			urlContent = urlContent + "&";
		dateObj = new Date();
		randContent = dateObj.getTime();
		arr_obj[idx].open("GET", urlContent + randContent, true);
		arr_obj[idx].send(null);
	}
}

function gsgSetImg(imgID, imgSrc) {
	var imgObj = false;
	imgObj = document.getElementById(imgID);
	if (imgObj)
		imgObj.setAttribute("src", imgSrc);
}

var gsgPopupWindow = false;
function gsgOpenPopup(url) {
	gsgPopupWindow = window.open (url, "myPopupWindow", "width=400,height=200,location=no,menubar=no,resizable=no,scrollbars=no,status=yes,titlebar=yes,toolbar=no");
	if (gsgPopupWindow) {
		gsgPopupWindow.focus();
	}
}

function isIE() {
	kkl_pos = navigator.userAgent.indexOf("MSIE ");
	return (kkl_pos>=0);
}

function numbers_only(myfield, e)
{
	var key;
	var keychar;

	if (window.event)
	   key = window.event.keyCode;
	else if (e)
	   key = e.which;
	else
	   return true;
	keychar = String.fromCharCode(key);
	// control keys
	if ((key==null) || (key==0) || (key==8) || 
	    (key==9) || (key==13) || (key==27)) {
	   return true;
	}   

	// numbers
	else if ((("0123456789").indexOf(keychar) > -1))
	   return true;
	else
	   return false;
}

function ie_keyup(myfield, e, for_what) {
	var keyup;
	
	if (!isIE()) {
		return true;
	}

	if (window.event)
		keyup = window.event.keyCode;
	else if (e)
		keyup = e.which;
	else
		return true;
	   
	// keys: delete, backspace
	if ((keyup==8) || (keyup==46)) {
		if (for_what && for_what=="reason_1") {
			//
		} else if (for_what && for_what=="reason_2") {
			//
		}
	   return true;
	} 
	return true;	
}

function frmLoginGS_Check(idx) {
	objTemp1 = document.getElementById("gs_email" + idx);
	objTemp2 = document.getElementById("gs_password" + idx);
	objTemp1.value = trim(objTemp1.value);
	if (!objTemp1.value || !isEmail(objTemp1.value)) {
		alert("Email không hợp lệ. Vui lòng nhập lại!");
		objTemp1.focus();
		return false;
	}
	if (!objTemp2.value) {
		alert("Vui lòng nhập vào mật khẩu của bạn!");
		objTemp2.focus();
		return false;
	}	
	return true;
}

function frmSearch_Check() {
	objTemp1 = document.getElementById("search_keyword");
	objTemp1.value = trim(objTemp1.value);
	if (!objTemp1.value) {
		alert("Vui lòng nhập vào từ khóa!");
		objTemp1.focus();
		return false;
	}	
	return true;
}

function swap_div(divID1, divID2) {
	objTemp1 = document.getElementById(divID1);
	objTemp2 = document.getElementById(divID2);
	if (objTemp1 && objTemp2) {
		strTemp = objTemp2.innerHTML;
		objTemp2.innerHTML = objTemp1.innerHTML;
		objTemp1.innerHTML = strTemp;
	}
}

function do_onload_default() {
	swap_div("header", "header_content");
	swap_div("left", "left_content");
	gsgLoadContent("/ajax/yahoo_chuyenmon.htm", "yahoo_chuyenmon", 8);
	gsgLoadContent("/ajax/yahoo_nhansu.htm", "yahoo_nhansu", 9);
}

function do_onload() {
	do_onload_default();
	if (window.do_onload_more) {
		do_onload_more();
	}
}