Differnt background graphics for each widget

Ok this is killing me.

I need to place a background image in a text widget for wordpress for a newletter sign up box. Im able to that with in the css:

“.textwidget{ width:198px; height: 147px; background-image: url(images/form.gif); “

the problem is the widgets have a default background image an it shows under the image i just made. Want to get rid of teh default image but keep it for the other widgets or possibly be able to define back ground images for each widget.

basically need to have a custom background image for each widget. In see the css and sidebar.php i see the widget calls but in the css there is only image for overall of the sideblock

Any help would I be great full