STATUS BAR TEXT NOT UPDATED

Question

hello, 
            in my application i am updating the status bar text property many a times as the different part of code is executed. However, i can see only the last update been performed.
ex:
               textBlock1.Text = " Launching your application. please wait ...";
               /// some code 
               textBlock1.Text = " i am ready !";
               // some more code here
                textBlock1.Text = " done !";

output is :: done !


Is this because the updates are performed very fast?If so how do i handle this situation ? I want the text to stay for some time on screen before the next update.

        I tried :  thread.sleep(1000); but looks like it is not the right way and it is not working. can anyone help me on this?
thank you