A mathematical riddle

Imagine there is a disease that afflicts just 1 in every 100 people in the population. A new test has been developed to detect the disease that is 99% accurate. That is, for people with the disease, the test correctly indicates that they have the disease in 99% of cases. Similarly, for those who do not have the disease, the test correctly indicates that they do not have the disease in 99% of cases.

If a person takes the test and the result of the test is positive, what is the probability that he or she actually has the disease?

I look forward to your responses :-)