Código html:
Ver original<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <script language="JavaScript" type="text/JavaScript"> function marcals_tots(){
if (document.form1.tots.checked){
document.form1.d1.checked=true;
document.form1.d2.checked=true;
document.form1.d3.checked=true;
}else{
document.form1.d1.checked=false;
document.form1.d2.checked=false;
document.form1.d3.checked=false;
}
}
<body><form name="form1" method="post" action=""> <table width="474" border="1" cellspacing="0" cellpadding="0"> En caso de ser
<b><u>TODOS
</u></b> marca aqu
í</td> <td><input name="tots" type="checkbox" id="tots" value="checkbox" onChange="marcals_tots()"></td> <td><input name="d1" type="checkbox" id="d1" value="checkbox"></td> <td><input name="d2" type="checkbox" id="d2" value="checkbox"></td> <td><input name="d3" type="checkbox" id="d3" value="checkbox"></td>
así se parece mas a lo que intentabas....
Quim