[Resolvido] Valida checkbox

[andreia_sp 1]

 

<script language="javascript">
function Valida(form){

var ok = false;
var form = document.forms[0].chk;

for (i = 0; i < form.length; i++) { 
 if (form[i].checked) { 
  ok = true; 
 }
}
if (!ok) {
 alert ("Selecione algum item.");
 return false;
 }
}
</script>

<form name="form" onsubmit="return Valida(this)">
<input type="checkbox" value="1" id="chk" name="item1"> Item 1
<input type="checkbox" value="2" id="chk" name="item2"> Item 2
<input type="checkbox" value="3" id="chk" name="item3"> Item 3
<input type="checkbox" value="4" id="chk" name="item4"> Item 4
<input type="checkbox" value="5" id="chk" name="item5"> Item 5
<br><br>
<input type="submit" value="Enviar">
</form>