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POBound javascript function
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  1. POBound javascript function
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    copied!<p>Alright my basic question is how do I simulate a button click in javascript.</p> <p>I know I have to use document.getElementById("btnSubmit").click(); but this doesn't seem to call the onClientClick javascript function as well.</p> <p>Enviorment:</p> <p>I am using ASP.NET with C# and javascript.</p> <p>What happened: I have an input text area and I want to make sure that users must enter a character before the submit button is enabled. I was able to do this with onkeypress="validateTxt();" which then called this function</p> <pre><code> function validateTxt() { var input = document.getElementById("&lt;%=txtUserName.ClientID %&gt;").value; //Need a min of 3 characters if(input.length &gt; 1) { document.getElementById("btnSubmit").disabled = false; } else { document.getElementById("btnSubmit").disabled = true; } } </code></pre> <p>The only problem though is doesn't register backspace.</p> <p>To solve this I found this online</p> <pre><code>&lt;script type="text/javascript"&gt; document.getElementsByName('txtUserName')[0].onkeydown = function (event) { if (event === undefined) event = window.event; // fix IE if (event.keyCode === 8) validateTxt(); if (event.keyCode === 13) { document.getElementById("btnSubmit").click(); } }; </code></pre> <p></p> <p>Now whenever the user presses the backspace my javascript function is called. This worked great up until I found out that when I press enter from the text area it wouldn't call my javascript function.</p> <p>Here is all of the relevant code...</p> <pre><code> &lt;script type="text/javascript"&gt; function InformUser() { window.document.getElementById("loadingMessageDIV").style.display = "block"; &lt;%=Page.GetPostBackEventReference(btnSubmit as Control)%&gt; document.getElementById("btnSubmit").disabled = true; } function validateTxt() { var input = document.getElementById("&lt;%=txtUserName.ClientID %&gt;").value; //Need a min of 3 characters if(input.length &gt; 1) { document.getElementById("btnSubmit").disabled = false; } else { document.getElementById("btnSubmit").disabled = true; } } &lt;/script&gt; </code></pre> <p>Here is the text area + javascript bounding function</p> <pre><code>&lt;asp:TextBox ID="txtUserName" runat="server" Font-Size="11pt" onkeypress="validateTxt();"&gt;&lt;/asp:TextBox&gt; &lt;script type="text/javascript"&gt; //We bind the textbox to this function and whenever the backspace key is pressed it will validateTxt document.getElementsByName('txtUserName')[0].onkeydown = function (event) { if (event === undefined) event = window.event; // fix IE if (event.keyCode === 8) validateTxt(); if (event.keyCode === 13) { document.getElementById("btnSubmit").click(); } }; &lt;/script&gt; </code></pre> <p>Here is the submit button</p> <pre><code>&lt;asp:Button ID="btnSubmit" runat="server" OnClientClick="InformUser();" OnClick="btnSubmit_Click" Text="Login" Font-Bold="True" Enabled="True" /&gt; &lt;script type="text/javascript"&gt; //Disable the button until we have some actual input document.getElementById("btnSubmit").disabled = true; &lt;/script&gt; </code></pre> <p>So to recap it does press the button, but it fails to disable it as well. I even tried to call the InformUser directly when the user presses enter and then press the button, but that didn't work either. </p> <p>I know it has something to do with how I bound the javascript function to the text area because when I take it out it works.</p> <p>Thanks for the help</p>
 

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