Numeric Comparison in switch statement

programming flash
1

Hello geeks!

First time working with numeric comparison, I found myself in dark, as below:

 
switch (_hours)
{
    case _hours = 0:
        _hours = 12;
        break;
    case _hours < 12:
        _hours = hours;
        break;
    case _hours = 12:
        _hours = 12;
        break;
    case _hours > 12:
        _hours = (hours - 12);
       break;
}

But, the code is not functioning. I don’t want to use if … else construct.
Would anybody kindly straighten this syntax, please! Any explaination, if necessary, would be highly appreciated.