I got to know how we do it.. Thanks to support in eCart . i went through this link & made it all..
I did by reading - - - Setting*the*WA*Database*Search*statement
Now product is getting added to cart when i type proper ProductName but facing only 1 single problem.. i m getting error when i click add to cart
Notice: Undefined variable: ATC_itemQuantity
Another thing is when directly we click Add to cart button all items from recordset gets displayed in cart.. & if we type any other product name in text field i get error like the same as above.. So please help on that... :)