delay = 1000;
imgNumber = 0;
totalimgNumber = 8; 
anim = new Array();

for (i = 0; i<totalimgNumber; i++) {
    anim[i] = new Image ();
    anim[i].src = '../images/animate/wave' + (i + 1) + '.jpg';
} 

    
function Switch() {                
    document.waveanim.src = anim[Math.floor(Math.random()*4)].src;    
    }
function animate() {
    Switch();
    setTimeout( "animate()", delay);
    }
 function fast() {
    delay-=10;
    if(delay<0) delay = 0;
    }
function slow() {
    delay+=10;
    if(delay>4000) delay = 4000;
    }