DIVs move as browser window is extended
New to the forum and relatively new to HTML and CSS, so signed up cause I'm having a bit of a problem with some DIVs moving around as the browser window is extended or made smaller. Can't post too much of the code as this is for a class assignment but should hopefully be enough to give you an idea of the problem.
These two elements appear next to each other, but the 'logoheader' div basically slides underneath the 'logo' div when the window is made smaller, and slides too far to the right of the 'logo' div when the window is extended to full size. Is there any way to fix these divs in one place or perhaps combine them into one div?