CSS/HTML - fix webpage to display footer correctly in IE9

There is a CSS issue with a website in correctly displaying the page footer at the bottom of the page. The same footer appears on all subsequent pages. In IE9/Safari (IPhone/IPad) the footer appears in the middle of the web page. The site's use of Quirks mode and doctype may be at issue and may need to have CSS and doctype adjustments to properly put it in Standards mode, so the footer moves to the bottom of the window. The solution should not be a hack but an accepted industry solution and support HTML5. The web page needs to correctly display the footer in IE9, Chrome 10, Safari 5.05 and Safari (IPhone), Opera 10.x and Mozilla 4.