Margin appearing at top of page

programming web dev
1

Hi Can anyone help?

How do i stop the margin (rougly 10px) automatcially appearing at the top of my webpage. I had solved the problem by using:

<body topmargin=“0”>

However when i submitted my site to the W3C Markup Vaildation Service… it picked <body topmargin=“0”> out as an error.

Does anyone know of another way of doing this perhaps using css?

Thanks