how to get values in SalesLine.Salesprice

hi i have created a new field called MRP Price in Config table. i want to show the value in salesLine.salesprice when the user chooses the particular configuration in salesline.

Can anyone tell me how to do tis?

In the modified method of the field InventDim → ConfigID write this code

salesLine.salesPrice = ConfigTable::find(salesLine.ItemId,InventDim.configId).MRP;

but this code is not working… i am nopt getting the value in salesprice field.