Syntax: dbo.fn_PercAdd(price, incr)
Output: (decimal) Returns the input price increased/decreased by incr percentage.
Input parameters:
price (decimal)  The price to increase.  incr (/+decimal)  When positive is the percentage of the increment, when negative is the percentage of decrement. 
Example:
dbo.fn_PercAdd(9, 20) returns 10.5dbo.fn_PercAdd(9, 20) returns 7.40
