Image Size - Help! - Photoshop 8.0

I made a bonehead move in creating this specific website in photoshop.

I opened a new document 700x500 and started to draw my header, footer, logos, text, etc. However, I made everything way to small. The whole image was supposed to be 700x500, instead I created it about half that size on the canvas.

Is there a way to get the whole image 700 x 500 without stretching it or changing the pixels? When I selected all and tried to free transform it stretched the image, looks grainy.

If I have to recreate the site I am going to be bummed.

See attached screenshot of the image work area

Thanks!
Daniel