I've got two html textboxes (txtFrom and txtTo) which is read-only. These two textboxes are used to show dates from datepicker.

My scenario is when txtTo textbox is filled with date i want to call a javascript which subtracts the two dates (txtTo - txtFrom) and enter the result in another textbox named txtDays.

How can i do this? I can't call onkeypress or onkeyup event since the textbox is read-only.

I've got two html textboxes (txtFrom and txtTo) which is read-only. These two textboxes are used to show dates from datepicker.

My scenario is when txtTo textbox is filled with date i want to call a javascript which subtracts the two dates (txtTo - txtFrom) and enter the result in another textbox named txtDays.

How can i do this? I can't call onkeypress or onkeyup event since the textbox is read-only.

• javascript
• html

• Why are you using text boxes for a read only field? – Des Horsley Commented Apr 28, 2013 at 22:27

3 Answers 3

You can use onchange event of javascript.

In html Section

<asp:TextBox ID="txtTo" runat="server" onchange="DateComparisionJavascriptFun();"></asp:TextBox>

In Javascript Block

<script type="text/javascript">
function DateComparisionJavascriptFun()
{
   alert("Validate dates here.");
}    
</script>

you should have callback function on that datepicker, when user selects a date it could call this function

dont know if its yours or third party datepicker but he should have defined callback when user selects a date and than it writes it to the text input, you should be able to add your function at this place

The onchange event only fires when the text field loses focus, so that probably won't work for you.

If you're programatically changing the text of the date field, then you should probably just change the other fields at the same time.

If you're going to be doing this sort of thing in more than one place, I'd highly remend using a data binding framework like Knockout JS, and use a ViewModel with a puted property.