@media screen and (min-width:0px) and (max-width:633px)
{
    #myF {
        display:none;
    }
    #login {
        padding-top: 0px;
    }
    #forgotPass
    {
        padding-top:0px;
    }
    #image1 {
        display: none;
    }
    #image2 {
        display: block;
    }
}

@media screen and (min-width: 629px) and (max-width: 792px) {   
    #img {
        height: 376px;       
    }
    #login {
        padding-top: 0px;
    }
    #forgotPass {
        padding-top: 0px;
    }
    #image2 {
        display: none;
    }
}

@media screen and (min-width: 781px) and (max-width: 2000px) {
    #myF {
        display: block;
    }
    #image2 {
        display: none;
    }
}