function chkcontrol1(j) {
var total=0;
for(var i=0; i < document.form1.first.length; i++){
if(document.form1.first[i].checked){
total =total +1;}
if(total > 1){
alert("Please Select only one image for first place")
document.form1.first[j].checked = false ;
return false;
}
}
} 

function chkcontrol2(j) {
var total=0;
for(var i=0; i < document.form1.second.length; i++){
if(document.form1.second[i].checked){
total =total +1;}
if(total > 1){
alert("Please Select only one image for second place")
document.form1.second[j].checked = false ;
return false;
}
}
} 

function chkcontrol3(j) {
var total=0;
for(var i=0; i < document.form1.third.length; i++){
if(document.form1.third[i].checked){
total =total +1;}
if(total > 1){
alert("Please Select only one image for third place")
document.form1.third[j].checked = false ;
return false;
}
}
}