Resizing the size of a 'box'

Hello

I have a 'test' Web page here: http://www.bayingwolf.com/India/contact.html

The white 'box' that holds the email form is governed by this little CSS piece in my external stylesheet:

#contentForm {	
width: 500px;	
margin: 0 0 0 382px;	
padding: 35px;	
background: #FFF;	
color: #5C5C5C;
}

Originally, this white 'box' was a fair bit wider than on the Web page now, but I managed to reduce it by changing the margin in the above script. I now wish to reduce its height a little and thought I could do something similar in the above script, but there is no property for me to alter.

Any advice, please?

Thank you.

Bluenose