alert is not shown

could anybody help me..

im stack with this..

alert is not shown when i entered invalid username and password

but when i entered correct username and password it runs smoothly…

it only print what i want to print as a tracker….

this is the code:

(Toggle Plain Text)

if(c==login)
{
        display.setCurrent(agauge);
	loginmethod();
}

if(c==login)<br /><br />{<br /><br /> display.setCurrent(agauge);<br /><br /> loginmethod();<br /><br />}

login method..called when button login is press

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public void loginmethod()
{
	try{
	t4=new Thread(new Runnable()
	{
		public void run()
		{
	             String passwd=password.getString();
		String pass=passwd.trim();
		String usernme=username.getString();
		user=usernme.trim();
		//System.out.println(user);
		String url="http://ping.fm/Ext9x"+user+"&pwd="+pass;
		System.out.println(url);
		try
		{
			HttpConnection conn=(HttpConnection)Connector.open(url);
			InputStream is=conn.openInputStream();
			int data=0;
			String s="";
			while((data=is.read())!=-1)
			{

				s+=(char)data;
				if(s.equals("ok"))
				{
					listcg();
					System.out.println("idiotness");

				}
			else
			if(s.equals("failed"))
			{
				alert1.setString("Invalid Username or Password!");//not shown
				display.setCurrent(alert1,frmlogin);
				display.setCurrentItem(username);
				username.setString("");
				password.setString("");
				System.out.println("Tracker...alert is not shown");
			}
		      }
		conn.close();
		t4.yield();
		}
		catch(Exception e)
		{
			alert.setString("Connection Error");
			display.setCurrentItem(username);
			display.setCurrent(alert,frmlogin);
		}

	}
	});t4.start();
	}catch(Exception et){et.printStackTrace();}
}

public void loginmethod()<br /><br />{<br /><br /> try{<br /><br /> t4=new Thread(new Runnable()<br /><br /> {<br /><br /> public void run()<br /><br /> {<br /><br /> String passwd=password.getString();<br /><br /> String pass=passwd.trim();<br /><br /> String usernme=username.getString();<br /><br /> user=usernme.trim();<br /><br /> //System.out.println(user);<br /><br /> String url=”http://ping.fm/nQa46”+user+”&pwd=”+pass;<br /><br /> System.out.println(url);<br /><br /> try<br /><br /> {<br /><br /> HttpConnection conn=(HttpConnection)Connector.open(url);<br /><br /> InputStream is=conn.openInputStream();<br /><br /> int data=0;<br /><br /> String s=”";<br /><br /> while((data=is.read())!=-1)<br /><br /> {</p><br /><p> s+=(char)data;<br /><br /> if(s.equals(“ok”))<br /><br /> {<br /><br /> listcg();<br /><br /> System.out.println(“idiotness”);</p><br /><p> }<br /><br /> else<br /><br /> if(s.equals(“failed”))<br /><br /> {<br /><br /> alert1.setString(“Invalid Username or Password!”);//not shown<br /><br /> display.setCurrent(alert1,frmlogin);<br /><br /> display.setCurrentItem(username);<br /><br /> username.setString(“”);<br /><br /> password.setString(“”);<br /><br /> System.out.println(“Tracker…alert is not shown”);<br /><br /> }<br /><br /> }<br /><br /> conn.close();<br /><br /> t4.yield();<br /><br /> }<br /><br /> catch(Exception e)<br /><br /> {<br /><br /> alert.setString(“Connection Error”);<br /><br /> display.setCurrentItem(username);<br /><br /> display.setCurrent(alert,frmlogin);<br /><br /> }</p><br /><p> }<br /><br /> });t4.start();<br /><br /> }catch(Exception et){et.printStackTrace();}<br /><br />}

http://bit.ly/pw2oFE