Create PDF form to calculate average income over period of time - repost

I need a PDF form document to use for calculating the average monthly income as entered by the user. I have included an example form. Form defaults no highlighting, no saving, no altering other than user input. Start Date: (must be no less than 90 days before today and auto-convert user input to required date format ie: 01012013->01/01/2013) End Date: (must no greater than 30 days from today and auto-convert user input to required date format ie: 02012014->02/01/2014) 2013 YTD Income: $ (auto convert user input to required format ie: 12330->$12,330, 1577521->$15,775; all money rounded to nearest dollar) 2013 Deductions: $ (this is deducted from YTD income before monthly income is calculated) 2014 YTD Income: $ (auto convert user input to required format ie: 12330->$12,330) 2014 Deductions: $ (this is deducted from YTD income before monthly income is calculated) Add Income? Yes/No (no is default, if yes another set of fields appear for input and calculation) GROSS MONTHLY INCOME: $ (combined YTD income - (minus) deductions / number of months between start-end dates to calculate the average monthly income based on 12 months and 365 days in a year) I am aware that Excel is a good way to accomplish this but I cannot use Excel due to restrictions.