I have 2 nested div\'s that should be 100% wide. Unfortunately the inner div with the Textbox overflows and is actually larger than the outer div. It has a left margin and overf
Add some css either in the head or in a external document. asp:TextBox are rendered as input :
input {
width:100%;
}
Your html should look like : http://jsfiddle.net/c5WXA/
Note this will affect all your textbox : if you don't want this, give the containing div a class and specify the css.
.divClass input {
width:100%;
}