Setting a random time interval for a slideshow?

1

hi,

this should be simple but its stumping me,

I am trying to make a slideshow that pulls random images at a random time interval (between 1 and 4 seconds). The images part works fine, and I can get the time function to create a random number, but that number doesnt change throughout the duration of the slideshow. I would like the duration to reset itself and changefor every picture that is displayed. Here is my code:

function allPlantPick(){

    setInterval("plantPick('plant1')", plantTimer());

}
    
function plantTimer() {

    var plantNum = (Math.random()*4000) + 1000;
    return(plantNum);
    
}

//this function works fine:
function plantPick(myFoo){ 

 var plantChoices=["images/p1.jpg","images/p2.jpg","images/p3.jpg"];
 
 document.getElementById(myFoo).style.backgroundImage = "url(" + plantChoices[ Math.floor(Math.random()*plantChoices.length) ] + ")";
}