Resizing the Textbox width

Hi,

I have a requirement of Resizing the Textbox width based on the maxlength of the textbox. i.e. I am adding textbox control dynamically with specific Maxlength value. For example, if the max length is 4 then the width of the textbox should be such that it can accommodate only 4 characters.

Please suggest, how this can be achieved with silverlight.

Thanks You,

Raj