By Chris Wright, The News On 6

TULSA, OK -- A court decision regarding Oklahoma's tough illegal immigration law could 'open the door' for big changes for every business in the state. A federal appeals court ruled on a temporary injunction against House Bill 1804 on Tuesday.

The court struck down two of 1804's provisions, but upheld another. State lawmakers say that provision could alter the hiring process in Oklahoma.

Since House Bill 1804 was passed in 2007, it has sparked lots of controversy, and caused plenty of confusion. Some of that confusion was clarified by a federal appeals court decision Tuesday.

Parts of the law were deemed unenforceable, but another was upheld.

Contractors who do business with state agencies will still be required to use the E-Verify System. It's a federal web site that allows employers to ensure that their employees are legally allowed to work in the United States.

But the appeals court ruling goes one step further, says 1804's author.

"It gave a green light to the authority of the state, should we choose to do so, to require basic pilot e-verify participation on the part of all employers," said Representative Randy Terrill, (R) -Moore.

It sounds like a simple requirement, but the Homebuilders Association of Tulsa says the system is far from ideal.

"This e-verify system had a lot of imperfections when it started. It was subject to a lot of false positives," said Paul Kane, CEO of the Homebuilders Association of Tulsa.

The Homebuilders Association says, in its current form, the law wouldn't affect many of its members because most, like this one, are private contractors."

But if the law is changes, and every employer is required to verify the eligibility of all of its workers, Kane says it could change the way Oklahoma does business.

"We have a great interest in seeing that laws that are passed to enforce immigration are not unduly burdensome on the small business owners of Oklahoma," said Paul Kane of the Homebuilders Association.

The Homebuilders Association of Tulsa was an outspoken opponent of 1804, but says the economy had proved more difficult to deal with than the law these past three years.