.clsmain
{
    width: 100%;
    height: 640px;
    border: 1px solid;
}

.clshdr
{
    width: 100%;
    float:left;
    border: 1px solid;
    /*height: 10%;*/
}

.clsleft
{
    width: 20%;
    float:left;
    border: 1px solid;
    /*height: 100%;*/
}

.clscntr
{
    width: 59.5%;
    float:left;
    border: 1px solid;
    /*height: 100%;*/
}

.clsright
{
    width: 20%;
    float:left;
    border: 1px solid;
    /*height: 100%;*/
}