Like in this blog hustlersblog.com the middle column is grey, and it goes to the bottom, when I set a columns background, only the area with content gets the background. thanks
There are several articles and discussions around the web that address this. The site in question is using a background image on the container to fake the column height. That particular column is indeed only as high as the content. There are workarounds like this one and several others. I suggest searching for phrases like equal height columns css and reading up on your options as there are many.
Here are some links you might find useful depending on where your strengths lie and what option you prefer: http://matthewjamestaylor.com/blog/perfect-3-column.htm http://www.ejeliot.com/blog/61 http://www.projectseven.com/tutorials/css/pvii_columns/index.htm http://himerusinc.com/tutorials/jQuery/using-dimensions-align-column-heights http://exscale.se/archives/2007/11/11/jquery-equal-height-elements-plugin/ http://bedrichrios.com/2008/02/06/equal-height-columns-again/