// Défilement 4 directions multiple 
function Defilant(id, pos_init, pos_min, pos_max, delta, direction) { 
   this.id          = id; 
   this.element     = document.getElementById(id); 
   this.pos_init    = pos_init; 
   this.pos_min     = pos_min; 
   this.pos_max     = pos_max; 
   this.pos_current = pos_init; 
   this.delta       = delta; 
   this.direction   = direction; 
} 

Defilant.prototype.defile = function() { 
   if (!this.element) { 
      this.element = document.getElementById(this.id); 
   } 
   if (this.element) { 
      if(this.direction == 'vertical'){ 
if(this.pos_current < (this.pos_min - this.element.offsetHeight) ){ 
            this.pos_current = this.pos_init; 
         } else if (this.pos_current > this.pos_max ) { 
            this.pos_current = this.pos_init - this.element.offsetHeight; 
         } else { 
            this.pos_current += this.delta; 
         } 
         this.element.style.top = this.pos_current+"px"; 
      } else if(this.direction == 'horizontal') { 
         if(this.pos_current < (this.pos_min - this.element.offsetWidth) ){ 
            this.pos_current = this.pos_init; 
         } else if (this.pos_current > this.pos_max ) { 
            this.pos_current = this.pos_init - this.element.offsetWidth; 
         } else { 
            this.pos_current += this.delta; 
         } 
         this.element.style.left = this.pos_current+"px"; 
      } 
   } 
}