I worked for a hospital until August 13, 2010.  The education nusre sent me to the ER, while I was on shift, because she thought I was having a stroke.  I have no insurance, therefore I got a big bill.  I resigned from my job on August 13, because i got a better offer with more pay.  I received a letter in the mail yesterday from the hospital saying they were keeping my last check to pay off the ER bill.  While employed there, I did sign a paper saying they could withhold 4% of my gross pay.  Can they legally take my last pay check like that?