[jQuery] Validate textbox if another textbox is filled

[jQuery] Validate textbox if another textbox is filled


Hi all,
how can I validate a textbox only if another textbox is filled (by the
user)?
<input name="txtControl" id="txtControl "type="text" />
<input name="txtValue" id="txtValue" type="text" />
I'd like to make "required" txtValue only if the user write something
in txtControl.
Has anyone ideas?
Thanks in advance.
Luis