stopping the child control from exceeding parent div element

i have a div element with a child control in it which gets populated with data

depending on data teh control expands and also the div. if i set the div width the data overflows in the extended control
i need to use clip property
i tried setting it but i am not getting teh result

clip:rect(0 30 30 0);

how do i set the parent and child element

This is not a html or css question; or at least I don't know what language you are using.

Can we see your code?
It's kind of hard to see the problem without it.

Note, that the clip property won't work if you set the overflow property to "visible".
See how it is supposed to work here.

Oops. Talk about jumping the gun. I wasn't thinking when I made my reply.

As Atli said, we need to see the markup or have a link. We also need to know which browser you are using. 'clip' only works in modern browsers and not IE.

Are you sure?
I just tested a very basic example in both IE6 and IE7 and they both seemed to do fine with it.

Not that it would greatly surprise me if there were some bugs lurking around that I missed.

I did not try it and I've never used it but here is my reference.

EDIT: A place I cannot link to says this:

Ok, I see.

After messing around a bit more with my code, I can confirm that quote.
Without the commas, it works with IE6 and IE7, but then it won't validate. If that doesn't bother you, all the other browsers also accept the comma-free version.

However, if you throw IE into quirks-mode (by omitting the doctype, for instance), it suddenly starts working with the standard method.
It's like they are ignoring the standards on purpose...

Of course they are! Always have. IE is the worst browser on the planet.

Try explicitly defining the width and placing an overflow:hidden; CSS propery on the parent element.