I'd like to improve the looks of some buttons on a web page.
I believe the code with the current buttons is this:

document.writeln('<input type="button" name="reset_button" value="Reset" onClick="resetForm();">
&nbsp;&nbsp;&nbsp;<input type="button" id="upload_button" name="upload_button" value="Upload" onClick="uploadFiles();">');
Someone suggested:
"I would leave the existing buttons and add background images via CSS. Something like this:
style="background: url('/your_button_image.png') no-repeat"
However, I don't know how to integrate this with the existing code.

Any additional help will be appreciated.