var globalTime = 0.0;
var nextTime = 0.0;
var mult = 1.0;

room.update = function(delta_time)
{
if(nextTime < globalTime)
{
nextTime = globalTime + (1000 * mult);
mult = Math.floor(Math.random() * 2) + 2;

}
globalTime += delta_time * mult;
var adjustedTime = globalTime/1000;
room.objects["walking"].blend0 = 0.5 + Math.sin(adjustedTime) * 0.5;
}