charts which update when a single cell changes

Hi everyone, I'm trying to create a chart that will update when a certain cell changes. The cell (A1) contains a drop down list which each month in it. I have a table with data in for all months. I want a chart that will change when a certain month is selected. So I would like when November is selected for November's info to be shown in a chart.
I've uploaded my spreadsheet for some help. The first tab has all the info. The second tab is a reporting tab. IDEALLY I would like a line chart that only shows information up to the month selected. so if May is selected I would like the bar chart to show information Jan-May. But I do not want it to show a zero value for months that have not been filled yet...
I hope this makes sense! Any help would be so appreciated.
Thank you