California State University, Channel Islands officials are trying to track down about 100 students who are eligible to enroll for the spring semester but haven't yet signed up for classes.

The 100 students are critical to the university because they will determine whether the school meets its enrollment target this year. The state budget crisis has made meeting that target imperative for the fledgling campus.

The university's final enrollment this year determines next year's enrollment, so a decrease would mean fewer students could enroll next year. But an increase over the target won't work either, because there is no state money to pay for additional students, said Ted Lucas, interim vice president for academic affairs.

"In the past, it was a good thing to go over, but this year we've been told we shouldn't go over," Lucas said. "We want to hit that goal as closely as possible, within 1 percent. Those hundred students put us right at the target."

Most of the unaccounted-for students are those who attended in the fall but haven't indicated yet whether they'll be returning for the spring. Classes resume on Monday.

"We really need to know if students are planning to come," Lucas said. "Their chances of getting the classes they want is better the sooner they enroll. And if they're not coming, we need to know. We can't let anybody else in until we hear from them."

If none of them enrolls, the university would be short of its goal. That's why officials are trying to contact the missing students. Last week, admissions staff members called the entire group but didn't reach many of the students.

A few students have said they don't plan to return in the fall, and some said the classes they need are full, but they're hoping to get added to the roster on the first day of classes, said Damon Blue, director of admissions and records.

He hopes more students will enroll as the first day of classes nears.

The easiest way to let the school know is to sign up for classes, which can be done on the university's Web site, Blue said.

Students can also call the admissions office at 437-8500.