I am using Tomcat5. I am trying to enlarge the small image in new pop up window. After clicking on the small image it shows the pop up window but it shows the code written in that jsp page not a image.
I don't think that you are going to get much in the way of substantive help with the information you have posted. Please read this for more information.
For example, how are you going about trying to show the bigger image? Without such information, only random guesses are possible.
but it shows the code written in that jsp page not a image.
Are you saying it shows some EL ? Java code cannot be viewed by any user but when EL is not recognized you can see EL code in the page. Can you post some examples ?