Need to add an gif on the inside of the asp button

Hi All,

I have one question.

How to add a gif image on asp Button.

Functionality : Asp button name is Submit and when we click on Submit button ,then submit text will be disappear and Gif image is loading on the same button. One Submit functionality has done then we need to show the button Name.

How can we do this. 

Can any one help me on this?.

Thanks in advance.