set x-y crossing on graph automatically
 

I have a graph set up where an input starts the range you want to look at. I
always want the "Y" to start at 0, and the scale nicely goes as high as
necesary for the numbers in the table (viscosity). If I want to look at the
100 degree temperature range starting at 0, the x axis works fine. but if I
choose to look at 50 and above, the "x" axis still starts with 0, leaving a
blank graph between 0 and 50 and still stopping at 100.

How can I set it so the x axis scale starts at the value selected?