.bigbutton1 {
background: url(grobalimage/bigbutton.png) no-repeat 0 -74px;
width: 190px;
height: 75px;
display: block;
text-indent: -5000em;
float:left;
}
.bigbutton1:hover {
background-position: 0px 0px;
}

.bigbutton2 {
background: url(grobalimage/bigbutton.png) no-repeat -190px -74px;
width: 190px;
height: 75px;
display: block;
text-indent: -5000em;
float:left;
}
.bigbutton2:hover {
background-position: -190px 0px;
}

.bigbutton3 {
background: url(grobalimage/bigbutton.png) no-repeat -380px -74px;
width: 190px;
height: 75px;
display: block;
text-indent: -5000em;
float:left;
}
.bigbutton3:hover {
background-position: -380px 0px;
}

.bigbutton4 {
background: url(grobalimage/bigbutton.png) no-repeat -570px -74px;
width: 190px;
height: 75px;
display: block;
text-indent: -5000em;
float:left;
}
.bigbutton4:hover {
background-position: -570px 0px;
}