populating text box based on drop down list

[lillyehrhart]

I have a text box called pro and a drop down list called scac. I am wanting to format the text box based on what is selected in the drop down. ex. pro is 1234564 and i want to format is based on the scac ABC to make it 1236-4564. I want to be able to add the format to be able to match how the scac code is formatted, whether it is separated by a space or a "-". If there is any information that i can give to help, then please let me know.

[Luk3r]

Do you have a current bit of code that you're trying and it isn't working? That'd be the first step.

[lillyehrhart]

i do not have any code for that because i am not really sure where to start.
here is my textbox for the pro

<div style="min-height: 5px;"></div>
                    <div style="padding-top: 3px; padding-bottom: 3px;">
                        <div style="float: left; width: 75px; text-align: right; padding-right: 5px;">Pro: </div>
                        <div style="float: left; text-align: left;">
                            <asp:TextBox ID="tbProNumber" Width="115px" runat="server"></asp:TextBox>
                            &nbsp;OR
                        </div>
                        <div style="clear: both"></div>
                    </div>

here is the code for the drop down list

  <div style="padding-top: 3px; padding-bottom: 10px;">
                        <div style="height: 18px">Carrier/SCAC </div>
                        <div style="text-align: center; width: 100%">
 
                            <asp:DropDownList runat="server" EnableViewState="true" ID="ddlScacs" AutoPostBack="True"></asp:DropDownList>
                            <div style="min-height: 4px;"></div>
                            <asp:DropDownList runat="server" EnableViewState="true" ID="ddlCarriers" Width="130px" AutoPostBack="True"></asp:DropDownList>
                        </div>

right now when you select something from the dropdown list, nothing changes in the pro text box

 Protected Sub ddlCarriers_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ddlCarriers.SelectedIndexChanged
        ddlScacs.SelectedIndex = ddlCarriers.SelectedIndex
    End Sub
 
    Protected Sub ddlScacs_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ddlScacs.SelectedIndexChanged
        ddlCarriers.SelectedIndex = ddlScacs.SelectedIndex
    End Sub

I do not have anything in the textchanged for the pro number yet.

i think that i would just populate the text box based on the selection from the carrier dropdown list and the scac dropdown list. every carrier has a different format for the pro. so i need to format the pro text box based on the selection. Some of them have the format of "123 1234 0" and others 12-123-456", they are different. please help!

[madankarmukta]

@lillyehrhart ,

May be this is the one you are looking for -

Adding a format to the TextBox in asp.net [closed]

Please let me know for any issues or clarifications.

Best Regards.