此代码为三列
body{
margin:0px;
font-family:arial,sans-serif;
color:#000000;
font-size:12px;
}
.screen {
margin:0px auto;
width: 905px;
}
.title {
background-color: #1753C3;
height: 44px;
width: 100%;
clear: both;
}
.adv {
background-image: url(images/adv.jpg);
background-repeat: no-repeat;
height: 124px;
width: 905px;
}
.logo {
background-image: url(images/logo.jpg);
background-repeat: no-repeat;
float: left;
height: 123px;
width: 215px;
}
.main {
width: 100%;
}

.bottom {
height: 140px;
width: 100%;
background-color: #1753C3;
clear: both;
}
.footer {
height: 30px;
width: 100%;
background-color: #6A88BF;
clear: both;
}
.main_left {
float: left;
width: 215px;
}
.main_right {
float: right;
width: 177px;
}
.main_center {
margin: 0px auto;
}