note 8046 added to rand

I've got a dilemna that the above posted solutions won't solve. I've got a table, with some rows marked as "active" and others as "in-active". I want to randomly select an ACTIVE row. Above methods people have posted do not do this. They assume that all rows can be chosen. To further complicate matters, I'd like to add a column that specifies a "probability to be chosen" (for example range 1-5). Basically I want some rows to have a higher probability to be chosen than others. I've been wrapping my brain around this for days with no luck..can anyone help? http://www.php.net/manual/function.rand.php