how can i call this javascript calculator?
<p>i hav this javascript code but the problem is that i am not able to call the html body part at client side in asp.net c#.so how can i call this javascript calculator when i click the button.</p>

<pre><code>&lt;script language="javascript"&gt;
var inputstring=" "
function updatestring(value)
{
    inputstring += value;
    document.calculator.input.value=inputstring;
}
&lt;/script&gt;

&lt;body bgcolor="white" topmargin="80"&gt;
&lt;center&gt;
&lt;table border=5 bordercolor=black  cellspacing=8&gt;
&lt;form name="calculator"&gt;
&lt;th&gt;
THE CALCULATOR
&lt;/th&gt;
&lt;tr align="center"&gt;
&lt;td&gt;
&lt;input type="text" name="input" maxlength=10 size=24&gt;
&lt;/td&gt;&lt;/tr&gt;
&lt;tr align="center"&gt;&lt;td&gt;
    &lt;input type="button" value="  +  " onclick="updatestring('+')"&gt;
    &lt;input type="button" value="  -  " onclick="updatestring('-')"&gt;
    &lt;input type="button" value="  /  " onclick="updatestring('/')"&gt;
    &lt;input type="button" value="  *  " onclick="updatestring('*')"&gt;
&lt;/td&gt;&lt;/tr&gt;&lt;tr align=center&gt;&lt;td&gt;
        &lt;input type="button" value="  mod  " onclick="updatestring('%')"&gt;
        &lt;input type="button" value="  0  " onclick="updatestring('0')"&gt;
        &lt;input type="button" value="  1  " onclick="updatestring('1')"&gt;
        &lt;input type="button" value="  2  " onclick="updatestring('2')"&gt;
&lt;/td&lt;/tr&gt;&lt;tr align=center&gt;&lt;td&gt;
            &lt;input type="button" value="  3  " onclick="updatestring('3')"&gt;
            &lt;input type="button" value="  4  " onclick="updatestring('4')"&gt;
            &lt;input type="button" value="  5  " onclick="updatestring('5')"&gt;
            &lt;input type="button" value="  6  " onclick="updatestring('6')"&gt;
&lt;/td&gt;&lt;/tr&gt;&lt;tr align="center"&gt;&lt;td&gt;
                &lt;input type="button" value="  7  " onclick="updatestring('7')"&gt;
                &lt;input type="button" value="  8  " onclick="updatestring('8')"&gt;
                &lt;input type="button" value="  9  " onclick="updatestring('9')"&gt;
&lt;/td&gt;&lt;/tr&gt;
&lt;tr align="center"&gt;&lt;td&gt;
                    &lt;input type="button" value="  clear  " onclick="input.value=' ';inputstring=' ' "&gt;
                        &lt;input type="button" value="  =  " onclick="input.value=eval(inputstring);"&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/form&gt;
&lt;/table&gt;
</code></pre>

<p>my button code is like this:</p>

<pre><code>&lt;asp:Button ID="BtnCalc" runat="server" Text="Calculator" OnClick="BtnSave_Click" /&gt;
</code></pre>
