In order to be treated as deductible alimony, payments made from you to your spouse (or ex-spouse) must meet all of the following requirements:
See for reference the IRS publication 504 - http://www.irs.gov/pub/irs-pdf/p504.pdf
The amount of alimony should be clearly identified in the divorce degree or separation agreement. If the amount of alimony depends on some circumstances - the divorce degree shroud clearly states how the amount should be determined and verified.
The amount of alimony is taxable income for recipient and deductible (as adjustment to the income) for payer.
Please let me know if you need amy help this matter.
If your alimony is based on your ex-spouse wages - the divorce degree should have a provision that allows you to verify that amount.
For instance - the divorce degree may specify that your husband is required to provide you with copies of his tax return, pay stubs, W2 forms etc.
If you have reasonable suspicious that he is cheating on the alimony payments - you may go back to the could and ask for modifications - so you will gain a control over the alimony determination.