Hi :>
You can not make client side dinamic effects useing PHP or any other server-side web programming language , but you can do it ! Its easy using a client-side java script code,
Try making a Java Script code like this ( I'm noth sure if this very code functions right or not , but the problem solution is in this way ) :
<form name=thisform>
<select name=op1 >
<option onclick="thisform.op2.add('have children');"> maried </option>
<option> not maried </option>
</select>
<select name=op2>
<option> no children </option>
</select>
</form>
Yours ,
Amin Rajaee amin_rajaee@yahoo.com