Addition of two variables in selenium IDE

Question

I have store one value in one variable and second in other, now i want to make addition of those two number.I am not able to do that, I have tried below code but its not working

<tr>
    <td>store</td>
    <td>6</td>
    <td>w</td>
</tr>
<tr>
    <td>store</td>
    <td>6</td>
    <td>x</td>
</tr>
<tr>
    <td>store</td>
    <td>javascript{storedVars['w'] + storedVars['x']}</td>
    <td>z</td>
</tr>
<tr>
    <td>echo</td>
    <td>${z}</td>
    <td></td>
</tr>

Answer 1

You have to use storeEval command

<tr>
    <td>storeEval</td>
    <td>${w}+${x}</td>
    <td>z</td>
</tr>