#verify_math{
    display:block;
    height:21px;    
}
#verify_math span{
    display:block;
    height:21px;    
    width:30px;
    position:relative;
    float:left;
    text-align:center;
    line-height:20px;
    color:#000;
}
#verify_math span.digital{
    background:url(./img/digi_img.jpg) left top no-repeat; 
}
#i_verify{
    position:relative;
    height:15px;    
    width:35px; 
    text-align:center;
    padding:0;
    margin:0;
    font-size:15px;
    font-weight:bold;
    font-family:Tahoma, Geneva, sans-serif;
}