#wz1
{
    width: 30%;
    background-color: #B8D7FF;
    float: left;
    height: 250px;
    text-align: center;
}

#wz2    
{
    height:250px;
    width:35%;
    float:left;
    background-color: silver;
    text-align: center;
}

#wz3
{
    width:30%;
    float:left;   
    height:250px;
    text-align: center;
}