Dynamic Scale for Chart on Dashboard

On my dashboard, I have a master list element with our budget cycles and the starting and remaining balance. In another element, I have a gauge chart to represent the selected budget cycle. The chart looks great and the needle correctly updates as I click on the different records in master list but I cannot figure out how to change the scale on the chart to go from 0 to the StartingBalance. If I can get the code into the ChartModify event, I already have the placeholder for it but how do I get other fields from the selected master record into the ChartModify event? I have a JS variable in the ChartModify event for 'strartingBudget' and when I hardcode '110000' into it, everything works great but I want to find a way to pass the selected starting budget into that variable. Any ideas?

Thanks!