function choose(){
var chk = document.getElementByNames("chb");
var count = 0; for(var i=0; i<chk.length; i++){
if(chk.checked){
document.getElementById("b1").innerHTML=" <input type=\"submit\" name=\"bb1\">";
count++;
}
} if(count == 0){
document.getElementById("b1").innerHTML="";
}
}
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<script language="JavaScript">
function choose(){
var name=document.getElementsByName("chb");
for(var i=0;i<name.length;i++)
{
if(name[i].checked)
{
document.getElementById("b1").innerHTML=" <input type=\"submit\" name=\"bb1\">";
break;
}
else
{
if(i+1==name.length)
{
document.getElementById("b1").innerHTML="";
}
}
}
}
</script>
</HEAD> <BODY>
<form>
<input type="checkbox" name="chb" value="checkbox" onclick="javascript:choose()">
<input type="checkbox" name="chb" value="checkbox" onclick="javascript:choose()">
<input type="checkbox" name="chb" value="checkbox" onclick="javascript:choose()">
<span id="b1"> </span>
</form>
</BODY>
</HTML>