can anyone fix my Css Wordpress Code

I am trying to add my header for the thesis theme in Wordpress. Does anyone know what i did wrong? Code:

/* This line sets up our clickable background image based on the site title’s link */
/* Adjust the height & width below to reflect the actual size of your image */
/* Change the filename of your image to reflect the actual header’s file name */.custom #header #logo a { display: block; height: 140px; width: 990px; background: url(’images/Logo.jpg’) no-repeat; outline: none; }

/* This line gets rid of the site title & tagline by casting them out to the far left */
.custom #header #logo, .custom #header #tagline { text-indent: -9999px; }

/* This line collapses the vertical space of the tagline so that there isn’t unnecessary white space after the header image */
.custom #header #tagline { height: 0; }

/* This line removes the padding from the header so that the background image sits close to the nav menu, the bottom border of the header, and the sides of the content */
.custom #header { padding: 0; }
/*

 

This line in custom.css looks to be the problem:
.custom #header {background: url(images/header.jpg) no-repeat; height: 25em; width: 50em;}

Change the height to 119px and width to 495px.

 

That did it. Thanks a lot.

 

Great!

I've never seen em being used for widths before. It's freaky but it works.
Must put it on my huge list of stuff to learn

 

Thanks, but for some reason the logo isn't displaying now. When I change it to Em it works but it doesn't work when I switch back to px.

Any ideas?