A new Alabama law may change the way some people cast their ballots.

Gov. Kay Ivey has signed a law that prevent crossover voting in the state. The bill, sponsored by Sen. Tom Whatley, specifically prohibits voters from casting a ballot for one party in a primary and then crossing over to vote in another party's runoff elections.

"It helps the Democrats choose Democratic candidates, it helps the Republicans choose Republican candidates. It just prevents the cross-over voting so you get a pure general election with a Democrat and a Republican," Whatley said.

Here are some things to know about the change:

I voted in Republican primary but want to vote in Democratic runoff. Can I?

No, but you weren't allowed to before the crossover voting ban was passed anyway. Democrats in Alabama have had a longstanding party rule prohibiting Republicans or anyone who voted in another party's primary from voting in their runoffs.

I voted in Democratic primary but want to vote in Republican runoff. Can I?

No, though you could have in the past. Alabama Republicans had no party rule preventing crossover voting.

Why the change?

Supporters of the bill said it prevents one party from exerting undue influence on the other party's race. Crossover voting has been a major issue in past state elections.

What if you're an independent?

You can still vote in the primary, but you'll have to pick a party during the primary and can only vote in that party's runoff.

What if you didn't vote in the primary?

If you didn't vote in either party primary, you're free to vote in the runoff of your choosing. The crossover rule only applies to those who cast a ballot in the primary and any subsequent runoffs.

What about the general election?

You can vote for whomever you want to during the general election, no matter which candidate or party you supported in the primary or runoff. The party choice doesn't bind you for future elections either, so if you vote in the Republican primary and runoff during one election cycle, you are free to vote Democratic in the next.

When will the law go into effect?

According to Secretary of State John Merrill, the new law will be enforced during the September runoff in the race for U.S. Senate. The primary for the Senate seat once held by current U.S. Attorney General Jeff Sessions will be held Aug. 15 with the runoff planned for Sept. 26.

Anything else?

The crossover voting ban bill also includes a provision that will allow for the replacement of paper sign-in sheets with electronic polling books. Any change from paper to electronic records would have to be approved by the County Commission and Probate Judge in the county or a municipal governing body where the election is being held.

The electronic books were used on a trial basis by 25 counties in the November 2016 election.

Updated May 30 at 2:35 p.m. to clarify that use of electronic books replacing paper sign-in sheets is allowed but not mandatory.