Problems with the height of/stretching a <div>

Hello! I have created this page www.cumdealer.com/pindsvin and everything works excellent (stretching <div>'s etc.), except the <div>'s colored red and blue on the site (#indhold_venstre og #indhold_hoejre). I need them to stretch 100% according to the height of #indhold_midt. I simply can not seem to figure this out - and it's really nagging me.

Thank you in advance,
fischer.

 

Have you tried <div style="height:100%;"> ??

 

yes... the style of the #indhold_venstre and #indhold_hoejre is as follows:

#indhold_venstre {
background-color: red;
min-height:100%;
width:400px;
float: left;
}

#indhold_hoejre {
background-color: blue;
min-height:100%;
width:400px;
float: right;
}