label text not changing in thread

i am using a thread in asp.net website. functions in thread runs fine but i want to update label text during execution of thread. but label text is not updating. i have worked on a desktop project where i used threads their i used delegates to update label and progress bar. it been a long time and i forgot how i used delegates. i searched for use of delegates in asp.net. but i have not got any solution. can any one help me?