v2.0
Código PHP:
<html>
<head>
<script language='javascript'>
function changeComboMode(oCombo, bEnabled){
if (bEnabled){
oCombo.disabled = false;
oCombo.focus();
} else {
oCombo.selectedIndex = 0;
oCombo.disabled = true;
}
}
function plan(val){
with (document.frm){
switch (val){
case 'A':
changeComboMode(selB, false);
changeComboMode(selC, false);
changeComboMode(selA, true);
break;
case 'B':
changeComboMode(selA, false);
changeComboMode(selC, false);
changeComboMode(selB, true);
break;
case 'C':
changeComboMode(selA, false);
changeComboMode(selB, false);
changeComboMode(selC, true);
break;
}
}
}
function valida(){
var bVal = false;
with (document.frm){
bVal = bVal || (selA.selectedIndex > 0);
bVal = bVal || (selB.selectedIndex > 0);
bVal = bVal || (selC.selectedIndex > 0);
if (!bVal)
alert('Debe seleccionar un plan');
else
submit();
}
return bVal;
}
</script>
</head>
<body>
<form name='frm'>
<input type='radio' name='rad' onclick='plan("A")'>
<select name='selA' disabled>
<option value=""> </option>
<option value="1">Plan A-1</option>
<option value="1">Plan A-2</option>
</select><br>
<input type='radio' name='rad' onclick='plan("B")'>
<select name='selB' disabled>
<option value=""> </option>
<option value="1">Plan B-1</option>
<option value="1">Plan B-2</option>
</select><br>
<input type='radio' name='rad' onclick='plan("C")'>
<select name='selC' disabled>
<option value=""> </option>
<option value="1">Plan C-1</option>
<option value="1">Plan C-2</option>
</select><br>
<input type='button' value='validar' onclick='valida()'>
</form>
</body>
</html>
Saludos.