datepicker update other text field on close/on change?

I have an event logger, for which I would like to extend its functionality, so that the event can be held over several days, so I need to add an end date field to my form.

What I would like to do is when the user chooses a start date with the datepicker, the end date field is updated to the same date automatically.

Hi Craig

Place the following script in the head of your document:

<script type="text/javascript">
function CopyValue(from, to){
  document.getElementById(to).value = document.getElementById(from).value;
  return true;
}
</script>

Then add this piece of code to the instance of your datepicker widget:

onblur="CopyValue('datepicker_1','datepicker_2')"

so that it would be like:

<input id="datepicker_1" name="datepicker_1" type="text" onblur="CopyValue('datepicker_1','datepicker_2')" />

Please replace "datepicker_1" and "datepicker_2" with the expressions, you use in your form.

Thanks Willi, works a treat !

Hi Craig

You're welcome

Thanks for the earlier tip.

I have changed the goalposts a little bit and am doing some extra stuff.

I have removed the onblur call from the CopyValue function and added it to a datepicker1 change function, so that the date is updated as before, and also the minDate for the 'dateto' field is set to be the same as the datefrom field, so the user cannot set a dateto which is earlier than date from.

so far so good.

What i can't get to work is adding a condition so that the dateto field is updated ONLY if it is currently empty, so if both fields have a value and the user decides to change the datefrom value, the dateto value is not affected.


here is my function as it stands...

$("#datepicker_1").change(
	function() {
    var test = $(this).datepicker('getDate');
    var test2 = new Date(test.getTime());
    test2.setDate(test2.getDate());

    $("#datepicker_2").datepicker("option", "minDate", test2);
	
	CopyValue('datepicker_1','datepicker_2');

	});

i tried to update the CopyValue function like so...

if(document.getElementById("datepicker_1").value = "") {

** do the update**

}

but it doesn't work.

this if statement:
if(document.getElementById("datepicker_1").value = "") {

is setting the value, not comparing, use "==" for comparison, and "=" for setting.

change the function to this:

function CopyValue(from, to){
	if(document.getElementById(to).value == '') {
  		document.getElementById(to).value = document.getElementById(from).value;
	}
  return true;
}

oops, schoolboy error !

thanks Jason