For the final div don’t use float, use overflow: hidden instead
.my_style_name {
/* float: left; Use overflow instead so that the remaining width is used*/
overflow: hidden;
}An example
http://jsfiddle.net/posco2k8/vu8dV
Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.