function loginButtonClick()
{
	if(document.getElementById("button").src.indexOf("login") > 0)
	{
		//alert("Login");
		login();
	}
	else
	{
	  //alert("Logout");
		logout();
	}
}
							
function login()
{
	if(document.getElementById("txtUsername").value.length == 0 || document.getElementById("txtPassword").value == 0)
	{
	  alert("A valid username and password is required!");
		return;
	}
								
	request = "./controls/login_process.php";
	params = "u=" + document.getElementById("txtUsername").value + "&p=" + document.getElementById("txtPassword").value
	result = processAjaxPostRequest(request, params);
								
	arr = result.split(":")
	if(arr[0] == 1)
	{
		//alert("Success..load user");
		displayUser(arr[1]);
	}
	else
	  alert("Login Failed. Please try again.");
}
							
function logout()
{
	request = "./controls/logout_process.php";
	params = "";
	processAjaxPostRequest(request, params);
								
	displayLogin();
}
								
function displayLogin()
{
								
	content =  "<table style=\"font-family:verdana; font-size:7pt; letter-spacing:1px;\">\n";
  content += "  <tr>\n";
  content += "  	<td width=\"5\"></td>\n";
  content += "		<td>USERNAME</td>\n";
  content += "		<td><input type=\"text\" id=\"txtUsername\" style=\"height:13px; width:100px; font-size:8pt;\"></td>\n";
  content += "	</tr>\n";
 	content += "	<tr>\n";
  content += "	  <td width=\"5\"></td>\n";
  content += "		<td>PASSWORD</td>\n";
  content += "		<td><input type=\"password\" id=\"txtPassword\" style=\"height:13px; width:100px; font-size:8pt;\"></td>\n";
  content += "	</tr>\n";		
  content += "</table>\n";
            		
  document.getElementById("loginContentArea").innerHTML = content;
  document.getElementById("button").src = "./images/login_submit.jpg";
}
							
function displayUser(full_name)
{
	content  = "<table style=\"font-family:verdana; font-size:11pt;\">\n";
  content += "  <tr>\n";
  content += "   	<td width=\"5\"></td>\n";
  content += "		<td>Welcome " + full_name + "</td>\n";
  content += "	</tr>\n";		
  content += "</table>\n";
            		
  document.getElementById("loginContentArea").innerHTML = content;
 	document.getElementById("button").src = "./img/logout.gif";
}