ActionScript 3.0 :: Slideshow With A Delay Of For Example 3 Seconds, And A Preloader Which Is A Line With A 100px Final Length?

i have a slideshow with a delay of for example 3 seconds, and a preloader which is a line with a 100px final length.i start preloading next image.now if the time until next image loads is longer than slideshow delay, i will show next image as soon as it loads.if the time until next image loads is shorter that than slideshow delay, i want to wait additional time until delay and then show the image.the problem is how do i represent smooth line width grow (being enter frame or tween) by calculating/comparing 2 values together (delay and loader percent, which goes from 0 - 100) ?if my line growth represent just a slideshow delay, then when it gets to an end, if next image still hasnt loaded, then it wont look good if line has come to an end, but i still have to wait.