I have a 3 form fields

<form name="datepick" id="datepick"....

<select name="dayselect" id="dayselect">
<option value="7">7</option>
<option value="14">7</option>
<input type="text" name="date1" id="date1" value="<% todaysdate %>">
<input type="text" name="date2" id="date1">

what i want to happen is when the user selects the number of days can the field called date2 be populated with the selected days to the date in date1.
i.e. if 7 is selected then 7 days are added to todays date.

thanks if anyone can help