combining multiple columns into one chart

[ks26]

good morning! I am trying to create a graph in Excel and having some difficulties, hopefully someone on here can help. Here is the situation: I have a table set up where users will enter daily readings from two scales. Not both scales are necessarily used on every day, sometimes both are used but not always. So i have 4 columns with dates and readings for each scale in dyamic ranges that I am trying to place on the same graph. The idea would be that if a certain scale wasn't used on a day the other one was there would just be a gap in the line graph. Thank you!

[avinashkale]

please provide sample data.