how we allow only alphabet and numeric values in textbox in asp.net(others are not valid like special chaacters)

hi,

Try this javascript
<pre lang="xml">&lt;script type=&quot;text/javascript&quot;&gt;

       function onlyAlphaNumeric(evt) {
           if (!(evt.keyCode &gt;= 48 &amp;&amp; evt.keyCode &lt;= 57)) {
               if (!(evt.keyCode &gt;= 65 &amp;&amp; evt.keyCode &lt;= 90)) {
                   if (!(evt.keyCode &gt;= 97 &amp;&amp; evt.keyCode &lt;= 122))
                       return false;
               }
           }
       }
   &lt;/script&gt;</pre>

calling of javascript function

protected void Page_Load(object sender, EventArgs e)
   {
      txtBox1.Attributes["onkeypress"] = "return onlyAlphaNumeric(event);";
   }