i need this code to take the item name and total price from my shopping cart in lines 4 and 6. can anyone help me urgently

html code supplied: 

<form action="https://www.payfast.co.za/eng/process" method="post">
<input type="hidden" name="cmd" value="_paynow">
<input type="hidden" name="receiver" value="***">
<input type="hidden" name="item_name" value="#imcarttext.imname">
<input type="hidden" name="item_description" value="kjhfdsaklfb">
<input type="hidden" name="amount" value="500.00">
<input type="hidden" name="return_url" value="http://www.mvgfitness.co.za/successful">
<input type="hidden" name="cancel_url" value="http://www.mvgfitness.co.za/unsuccessful">
<input type="image" src="http://www.payfast.co.za/images/buttons/buynow_basic.gif" width="95" height="26" alt="Buy Now" title="Buy Now with PayFast">
</form>