hi all.. one more newbie here.. :-)

i have a set of master & detail tables in SQL database. and now i am about to design a web page for these tables for end user where he can add a new record to this set of tables..

lets say my two tables are 1.QUOTATION MASTER, 2. QUOTATION DETAIL
now i need to design a screen where end user will select a customer name and then few products he'll select one by one and at the end he'll press 'save quotation' button.. at this point of time the list of products he has selected should be saved in 'QUOTATION DETAIL' and the customer info in 'QUOTATION MASTER' table.. whatever modifications he do before pressing 'SAVE QUOTATION' button should be handled client side without doing round trips to the server and i only need to save the 'QUOTATION DETAIL' at the end after all the confirmations from the end user, if in any case the user leaves the screen in the middle or closed the screen without any confirmations all the information will be discarded.. but if i use a GRID component linking to the 'QUOTATION DETAIL' whenever user adds a product from the selection, this will be added to the grid and this will be stored in 'QUOTATION DETAIL' immediately.. lets say he has added 3 products and he closed the web page abruptly, then all this unwanted 3products data is already in the 'QUOTATION DETAIL' table which is not supposed to be in actual situation.

i hope i made it clear what i need.. is there any advice or suggestion for designing this screen, or is there any way that this grid will be linked to some temporary data set and whatever editing done to this dataset will be handled without the interaction with actual database until the user press 'save' button? or is it a better way to store this information in an XML file or something? can we link a grid component to an XML file? i have only seen a GRID can be linked to an SQL table or SQL query.. :-(