How do I find out and change the value of in asp.net?

Question

I want to find the value of and want to mask the first 4th of the text field to another character when the length of the text field is 4 or greater.

but I don't know well asp.net skill. help me plz.

here is some html in body tag

<body>
    <form id="form1" runat="server">
        <div>
            <input type="text" runat="server" id="input1" name="input1" value="TestText" />
            <input type="button" runat="server" class="btnCnvt" name="btnCnvt" id="btnCnvt" value="convert" onclick="GetValue()" />
        </div>
    </form>
</body>

here is javascript :(

<script type="text/javascript">
        function GetValue()
        {
              // Don't Work!!!(not fount 'value' attribute)
              var str = document.getElementById("input1").value;
        }
</script>

In your browser, please `View Source`. Update your question with the HTML that was generated from your code fragment (so we can see what HTML that code resulted in). — mjwills, May 30 '19 at 02:51
First I'll input some string in the textbox(input1), and click the btnCnvt button! — JuniorDev, May 30 '19 at 03:44

score 0 · Answer 1 · edited May 30 '19 at 05:07

0

Your button is from server side, So, javascript function will not fire on OnClick event, instead use OnClientClick event.

edited May 30 '19 at 05:07

Naing Lin Aung

3,373
4
31
48

answered May 30 '19 at 02:29

Lakhwant Singh

61
1
6

How do I find out and change the value of in asp.net?

1 Answers1