Detailed Ecart Help..

I created all pages using ecart of webassist.. now for payment i m not using PAYPAL as in india there is a company called "CCAVENUE" which support all local banks payments in INDIA. so i have registered there.. i m using dataassit & all the products are stored in my db.

now prob i m facing is during payment i.e when i click proceed to checkout they have there own CHECKOUT page with there setting so the money gets transferred to my a/c.. now when i click checkout, it shows an error at AMOUNT @ line 536
Parse error: syntax error, unexpected T_STRING in /home/content/67/8603867/html/gatewayCheckout.php on line 536

I have attached file please check all of them..

when i set the amount value i.e like direct value 100, 20 o so then everything works fine.. & same is happening to ORDER ID.. this ORDER ID is related to payment process to store random ORDER ID @ CCAVENUE(payment gateway) so i used security assist random password 6digits. when i apply that then below error is shown:

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in /home/content/67/8603867/html/gatewayCheckout.php on line 537


then if i enter a value in ORDERID then everything process well.. So these are the problems i m facing.. please help on this ASAP.