How to pass a value into a javascript function within an aspx page onClientClick

asp.net, javascript

Solution

Something like that :

<asp:textbox id="txt1" runat="server />

<asp:LinkButton ID="LinkButton1"
                runat="server"
                Text="Save" 
                onclick="Save"
                OnClientClick="check(document.getElementById('<%=txt1.ClientID%>').value;)"
                />

Edit: Other methods :

You can add it on server side : `LinkButton1.OnClientClick="check(document.getElementById('" + txt1.ClientID + "').value;)"`;

If you want to remain in the aspx page, you have to put a name of a javascript function in the OnClientClick and implement the javascript function in a script tag :

<asp:LinkButton ID="LinkButton1"
                runat="server"
                Text="Save" 
                OnClientClick="validate();"
                />
<script type="text/javascript">
    function validate() {
        alert(document.getElementById('<%=txt1.ClientID%>').value);
        return false;
    }
</script>

Problem

I want to check the textbox value before postback occurs. I set the `onClientClick` value to my function but I don't know how to pass the data to check, in this case I want to check the txt1 entered text. ``` <asp:textbox id="txt1" runat="server /> <asp:LinkButton ID="LinkButton1" runat="server" Text="Save" onclick="Save" OnClientClick="javascript:check(WANT TO PUT TEXTBOX VALUE HERE);" /> ``` My javascript: ``` function check(txt) { var pattern = /^[0-9]{1,11}(,[0-9]{0,2})?$/; if (!pattern.test(txt)) { return false; } else { return true; } } ``` The issue is that this check function is used along the keypress event of the txt1 so I cant use: ``` function check(){ var txt=$('#txt1').val(); } ``` The whole JS code: ``` $('#txt1').keypress(function (e) { var key = String.fromCharCode(e.which); var txt = $(this).val() + key; if (check(txt)) { // do sth } else { e.preventDefault(); // do sth } }); ``` How can I tell the OnclientCLick function to get the txt1 value? Thank you.

Original source