Bills undergo three or four readings during the legislative process. After the first reading, they are assigned to committee. Committees can amend measures or hold legislation and prevent it from advancing. Once committee action is completed, the bill undergoes a second hearing and a third hearing, which happens just before the floor vote on it. The bill is then sent to the opposite legislative house for consideration. If approved, without amendment, it is sent to the governor. If there is amendment, however, the Senate may either reconsider the bill with amendments or ask for the establishment of a conference committee to work out differences in the versions of the bill passed by each chamber. Once a piece of legislation approved by both houses is forwarded to the governor, it may either be signed or vetoed. If it is signed, it takes effect on the effective date of the legislation. If it is vetoed, lawmakers may override the veto with a vote by a three-fifths majority in both chambers.