How to force an point in x-axis to appear in plot

Dear all,

With this snippet:
xlim=c(-126000,500000)

in the current plot, the x-axis appear ?in the following tick marks:

-100000, 100000, 300000, ...etc

How can we force a point where x=0 to appear in the plot?
Yielding:

-100000, 0, 100000, 300000, ...etc
               ^

in the x-axis tick marks.

- Gundala Viswanath
Jakarta - Indonesia