title: Calculation using jquery onkeypress
body: <p>I have this type of exercise in jquery. Go here <a href="http://jsfiddle.net/LAntL/3/" rel="nofollow">http://jsfiddle.net/LAntL/3/</a></p>
  
  <p>For <code>Item 1</code>, if I add #no of quantity of <code>Size 7</code>, it should be <code>multiplied by Item 1's Price</code> displayed in text box and the result should be shown in <code>Item 1's Ext</code> textbox.
  then if I do same for <code>size 8.5 of Item 1</code>, it should perform the same.</p>
  
  <p>But the Ext will have <code>(Price x Size 7 Qty) + (Price x Size 8.5 Qty)</code></p>
  
  <p>Same will happen for <code>Item 2</code>. And along with this, <code>Total quantity and Total price</code> will be updated on <code>keypress</code> event of each textbox.</p>
  
  <p>I'm a beginner in jquery and got this killing exercise.
  Please help someone.</p>
  
  <p>Thanks in advance.</p>