i have just set zen cart and got everything how i want it up ive gone to test the payment procedure and when i go from my shopping cart to checkout it comes up with a blank white page and i cant do anything have i missed something i have only chenged the style sheet to fit the logo on and had someone help me that new what they are doing anything else i have not touched

i dont want to have to redo everything as this hapend before so i uninstalled it and re did it

thankyou