title: configurable product price does not change auto after select option from dropdown in magento
body: <p>Magento configurable product does not change price as I select options from dropdown. I am using a custom theme. </p>
  
  <p>for example : Parent Product has two sizes Size 1 and Size 2. 
  Size 1 is of $100,
  Size 2 is of $200</p>
  
  <p>As I select Size 2 the price on product detail page should changed to $200</p>
  
  <p>What are the steps? </p>