Change button style

I've done some research in the forum - haven't found exactly the solution.

I simply want to change my button style to this.
{CJATTACHMENT }

I've found that if i use Inspect code in chrome and find the class of the button (ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only):
{CJATTACHMENT }
{CJATTACHMENT }

and change the class to simply: class="button" (from my template)
{CJATTACHMENT }

It will change the button to exactly how i want it - it will look like all the rest of the buttons on my website.
{CJATTACHMENT }

But - I run into this dead end: In the template file i see:

<a href="#" onclick="javascript: return false;" id="continuebutton"

and it stops there without saying what class - i guess it pulling the classes from somewhere else. I can't figure out where i need to remove these classes from the button "ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" and replace them with this class "button"

All the help would be help full. Thank you so much.