actionscript 3 - AS3 Array Display button not working properly -

i'm working on program learn how use arrays in computer course , display button doesn't work after first press. first time click it, works , displays 2nd time stop showing first value , starts showing last value twice, 3rd time cuts off 2nd value , displays last value 3 times , on. , when press button find sum of values gives me sum of of values show after hit display button. here's code, , sorry french commentary, it's school.

function afficherfunction(event:mouseevent):void  {    // compose cette fonction visant à afficher tous les éléments du tableau.   txtsortie.text = "";   var entier:int;   entier = -1   (var i:int=entier; < mesentiers.length; i++)     {         if (i+1 < mesentiers.length)         {         mesentiers[i] = mesentiers[i+1];         affichage = affichage + mesentiers[i] + "\n"         }     }   txtsortie.text = affichage;   affichage = "";   = -1; } //fin fonction afficher. 

mesentiers[i] = mesentiers[i+1];

this line problem. not sure meant line doing, it's setting value @ index i value @ next index--essentially shifting values down 1 (and losing value @ index 0).