[jQuery] how to check if a form has changed

[Sridhar]

Hi,

     we are trying to give a feedback to the user if the user has
changed some values in the form and tries to close the form with out
saving the changes. is there a plug-in that can check this? or do I
have to loop-through each control and check if the value has changed
by comparing the value with the stored value in a hidden variable? If
there is a standard way to do this, please let me know. we are using
asp.net to create the forms

Thanks,
sridhar.