I'm stuck in my first script

@andr�_4582 

I’m not really good with ScriptUI, so I created some "simplified" examples of the standard dialogs in Photoshop such as confirm() to try to understand the process of linking things up to the buttons:

https://github.com/MarshySwamp/ScriptUI-Confirm-Window

See if that makes sense to you, looking at the comments.

You just need to move everything at the bottom into the if block, you don't even need the else block, I just put it there for clarity.

I used part of that for your script, changing everything from line 156 onwards:

//
// ============SCRIPT DE REDIMENSIONNEMENT POUR CONCOURS CLUB ============// 

var nom;
var prenom;  
var choix ;
var type;


app.preferences.rulerUnits = Units.PIXELS;			// L'uniti de base sera le pixel
app.displayDialogs = DialogModes.NO;				// Le script est muet


// Vérifie la présence d'un document ouvert et lui donne un nom
var nbr = documents.length; 
if (nbr == 0) 
    { 
     alert("Vous devez d'abord ouvrir un fichier"); 
    } 
else

//
// ==============Dimension  Maximale (hauteur ou largeur) fixié dans DimMax	
//
var DimMaxH =1920;
var DimMaxL =1920;

 
//
//============== Récupération de côtes de l'image et calcul du ratio
//
     var largeur = app.activeDocument.width.value;
	var hauteur = app.activeDocument.height.value;
    MonImage = app.activeDocument;
    
 //   
//============= J'applique les nouvelles dimentions  avec une résolution de 120 et en respectant le Ratio. 
//
    if ((app.activeDocument.width/app.activeDocument.height >= 1) && (largeur>DimMaxL)){
		//mode paysage ou carré on prend en référence la largeur
           //alert("Boucle Horzontale");
           var Ratio = (DimMaxH/largeur);
           MonImage.resizeImage (largeur*Ratio,hauteur*Ratio ,120,ResampleMethod.BICUBIC);
      }
	else
    
    
     if ((app.activeDocument.width/app.activeDocument.height < 1) && (hauteur>DimMaxH)){
		//mode portrait; on prend en référence la hauteur
         //alert("Boucle Verticale"); 
         var Ratio = (DimMaxH/hauteur);
         MonImage.resizeImage (largeur*Ratio,hauteur*Ratio ,120,ResampleMethod.BICUBIC);
      }
     else
     
     
    if((largeur<DimMaxL) && (hauteur<DimMaxH))
     //Si l'image est en dessous de la dimensions 
      {
       MonImage.resizeImage = app.activeDocument;
      }
    
        
      
   

//    Création d'une boite de dialogue pour  identifier l'auteur et le choixs des concours
  
// DIALOG
// ======



var dialog = new Window("dialog"); 
    dialog.text = "Redimentionnement pour concours F.F de Photographie"; 
    dialog.orientation = "row"; 
    dialog.alignChildren = ["left","top"]; 
    dialog.spacing = 10; 
    dialog.margins = 16; 

// GROUP1
// ======
var group1 = dialog.add("group", undefined, {name: "group1"}); 
    group1.orientation = "column"; 
    group1.alignChildren = ["fill","top"]; 
    group1.spacing = 10; 
    group1.margins = 0; 

// Panneau Non et Prénom
// ======
var panel1 = group1.add("panel", undefined, undefined, {name: "panel1"}); 
    panel1.text = "Auteur"; 
    panel1.preferredSize.height = 150; 
    panel1.orientation = "column"; 
    panel1.alignChildren = ["left","top"]; 
    panel1.spacing = 10; 
    panel1.margins = 10; 
 

var statictext1 = panel1.add("statictext", undefined, undefined, {name: "statictext1"}); 
    statictext1.text = "Entrez votre nom"; 
   var edittext1 = panel1.add('edittext {properties: {name: "edittext1"}}'); 
    edittext1.text = " "; 
    edittext1.preferredSize.width = 120; 
    edittext1.preferredSize.height = 23; 
var statictext2 = panel1.add("statictext", undefined, undefined, {name: "statictext2"}); 
    statictext2.text = "Entrez votre prénom"; 
var edittext2 = panel1.add('edittext {properties: {name: "edittext2"}}'); 
    edittext2.text = " "; 
    edittext2.preferredSize.width = 120; 
    edittext2.preferredSize.height = 23; 


// Groupe concours
// ======
var group3 = dialog.add("group", undefined, {name: "group3"}); 
    group3.orientation = "column"; 
    group3.alignChildren = ["fill","top"]; 
    group3.spacing = 10; 
    group3.margins = 0; 

// Panneau Choix et Type de concours
// ======
var panel2 = group3.add("panel", undefined, undefined, {name: "panel2"}); 
    panel2.text = "Chois des concours"; 
    panel2.preferredSize.height = 150; 
    panel2.orientation = "column"; 
    panel2.alignChildren = ["fill","top"]; 
    panel2.spacing = 10; 
    panel2.margins = 10; 

var statictext2 = panel2.add("statictext", undefined, undefined, {name: "statictext2"}); 
    statictext2.text = "Couleur / Monochrome"; 
var dropdown1_array = ["Couleur","Monochrome"]; 
var dropdown1 = panel2.add("dropdownlist", undefined, undefined, {name: "dropdown1", items: dropdown1_array}); 
   dropdown1.selection = " ";
    
    
 var statictext3 = panel2.add("statictext", undefined, undefined, {name: "statictext3"}); 
    statictext3.text = "Type de concours"; 
var dropdown2_array = ["Papier","Papier Nature","Nature Image Projetée ","Image Projetée","Concours Auteurs"]; 
var dropdown2 = panel2.add("dropdownlist", undefined, undefined, {name: "dropdown2", items: dropdown2_array}); 
   dropdown2.selection = " "; 

// Groupe Validation ou Abandon
// ======
var group4 = dialog.add("group", undefined, {name: "group4"}); 
    group4.orientation = "column"; 
    group4.alignChildren = ["fill","top"]; 
    group4.spacing = 10; 
    group4.margins = 0; 

    var button1 = group4.add("button", undefined, undefined, {name: "ok"}); 
    button1.text = "OK"; 
    var button2 = group4.add("button", undefined, undefined, {name: "cancel"}); 
    button2.text = "Cancel"; 
    
  

// Groupe Validation ou Abandon
// ======
if (dialog.show() === 1) {

    var nom = edittext1.text
    var prenom = edittext2.text
    var choix = dropdown1.selection;
    var type = dropdown2.selection;
    alert(nom + "__" + prenom + "__" + [choix] + "__" + [type] + ".JPEG", "Enregistrement du Fichier");
    nouvDocument = (nom + "__" + prenom + "__" + [choix] + "__" + [type] + ".jpg");

    var dossier = Folder.selectDialog("Selectionner le Dossier pour l'enregistremnt");
    var docRef = activeDocument
    var dossierDoc = dossier + "/" + nouvDocument

    jpegOptions = new JPEGSaveOptions();
    jpegOptions.quality = 12;
    jpegOptions.embedColorProfile = true;
    jpegOptions.formatOptions = FormatOptions.STANDARDBASELINE;
    jpegOptions.matte = MatteType.NONE;
    docRef.saveAs(new File(dossier + "/" + nouvDocument), jpegOptions);
    app.activeDocument.close(SaveOptions.DONOTSAVECHANGES); 

} else {
    alert("Script cancelled!");
}