function choseyearmonth(obj,m,y)

					{

						

						var t;

						t=obj.selectedIndex;						

						obj.options.length=1;

						var ngay=0;

						switch(m)

						{

							case "4":	

							case "6":

							case "9":	

							case "11":

								ngay=30; 

							break;

							case "2":

							if(eval(y)%4==0)							

							{

								ngay=29;

							}

							else

							{

								ngay=28;

							}

							break;

							default:

							ngay=31;

						}						

						for (var i=1; i<=ngay;i++){						

						obj.options.add(new Option(i,i));

						}

						if(t<=ngay)

						{

							obj.options[t].selected=true;

						}

					}


// ham kiem tra xem xau co phai la nhap o dang so hay khong

function isNubers(str)

{

var isOK=true;

for(var i=0;i<str.length;i++)

	{

		if(str.charAt(i)<'0' || str.charAt(i)>'9')

			{

				isOK=false;

				break;

			}

	}

	return isOK;	

}

// ham kiem tra xau xem co phai la xau rong hay ko

function isWhitespace (s)

{   

	var whitespace = " \t\n\r";

	var i;

	var j=0;

  for (i = 0; i < s.length; i++)

  {   

    var c = s.charAt(i);

	if (c==' ')

	{j++;

	}

	else{

    if (whitespace.indexOf(c) == -1) return false;

	}



  }

  if (j!=s.length)

  {return false;

  }

  return true;

}



function get_object(idname)

{

	if (document.getElementById)

	{

		return document.getElementById(idname);

	}

	else if (document.all)

	{

		return document.all[idname];

	}

	else if (document.layers)

	{

		return document.layers[idname];

	}

	else

	{

		return null;

	}

}



function get_tags(parentobj, tag)

{

	if (typeof parentobj.getElementsByTagName != 'undefined')

	{

		return parentobj.getElementsByTagName(tag);

	}

	else if (parentobj.all && parentobj.all.tags)

	{

		return parentobj.all.tags(tag);

	}

	else

	{

		return null;

	}

}





var xmlHttp;

function createXMLHttpRequest() {

	if (window.ActiveXObject) {

		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");

	}

	else if (window.XMLHttpRequest) {

		xmlHttp = new XMLHttpRequest();

	}

}



function startRequestHTML(strUrl, strDivName) {

	createXMLHttpRequest();

	window.scrollTo(0,0);

	xmlHttp.onreadystatechange = function(){

		if(xmlHttp.readyState == 4) {

			if(xmlHttp.status == 200) {

				get_object(strDivName).innerHTML = xmlHttp.responseText;

			}

		}

	};

	xmlHttp.open("GET",strUrl, true);

	xmlHttp.send(null);

	return false;

}





function stateLoad(obj)

{

	get_object(obj).innerHTML='<div class="loading">Loading data...</div>'



}

function loadXMLDoc(url, callbackFunction, divDesc, QUERY_STRING) {

	aFlag=false;

    // branch for native XMLHttpRequest object

    if (window.XMLHttpRequest) {

        xmlHttp = new XMLHttpRequest();

		xmlHttp.onreadystatechange =	function(){

										// only if req shows "complete"

										if (xmlHttp.readyState == 4) {

											if(divDesc) stateLoad(divDesc);

											eval(callbackFunction);

										}

									}

		if(QUERY_STRING){

		    xmlHttp.open("POST", url, true);

			xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

			xmlHttp.send(QUERY_STRING);

		}

        else{

	        xmlHttp.open("GET", url, true);

	        xmlHttp.send(null);

	    }

    // branch for IE/Windows ActiveX version

    } else if (window.ActiveXObject) {

        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");

        if (xmlHttp) {

        	xmlHttp.onreadystatechange =	function(){

											// only if req shows "complete"

											if (xmlHttp.readyState == 4) {

												if(divDesc) stateLoad(divDesc);

												eval(callbackFunction);

											}

										}

			if(QUERY_STRING){

			    xmlHttp.open("POST", url, true);

				xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

				xmlHttp.send(QUERY_STRING);

			}

			else{

			    xmlHttp.open("GET", url, true);

			    xmlHttp.send(null);

			}

        }

    }

}



function openWin(strUrl, strName, strFeatures)

{

	var objWin = window.open(strUrl, strName, strFeatures);

	if(!objWin) {

		alert("L×i: Không thà mß cía sÕ éng dång!\nB¡n vui lòng t¯t chéc n
ng ch·n popup cça trình duyÇt và thí l¡i.")

		return false;

	}

	return true;

}





function advClick(strURL)

{

	return openWin(strURL,"_blank","scrollbars=yes, toolbar=yes, menubar=yes, status=yes, resizable=yes");

}



function checkEmail(checkStr) 

{

	if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(checkStr))

	{

		return (true)

	}

	return (false)

}