I have an excel vba program where I need to cycle through a column of invoice numbers and determine if the number has already appeared in the column. So I need to check an array or collection of numbers. If the number is there, I need to delete the row and move on to the next row. If the number is not in the array, I need to add it to the array and then move on to the next row. I know how to cycle through the rows, but I don't know how to add a record to an array nor how to check to see if a record already exists in an array.