Hi,

Assuming you are using MS Graph.
For data in columns use the first column for X values and subsequent columns
for Y data.
In this example data set ~ is used to place hold an empty cell.

A    B    C
1    1    ~
2    2    ~
3    3    ~
4    4    ~
5    5    ~
1    ~   6
2    ~    5
3    ~    4
4    ~    3
5    ~    2

Cheers
Andy