COLUMN CHART IS NOT SHOWING IN SSRS REPORT?

In SSRS report ,

As per requirement  of Chart (P_SSN vs Amount) ,

I configured like below attached image:

                                category X-axis=P_SSN

                                Value  Yaxis = Amount

and chart type is COLUMN

You can see the out put of Query in Patient Charge slip

but result query displaying in preview but Graph is not showing (but Legend is showing i.e., see the attached image)

So please help on Showing COLUMN graph in the chart.

Thanks

--Madhu