var myDoc = app.activeDocument;

var myLanguages = new Array();

for (j=0;j<app.languagesWithVendors.length;j++){
	myLanguages.push(app.languagesWithVendors[j].name);
	}

myDlg = new Window('dialog', 'Selecteer de taal');
myDlg.orientation = 'column';
myDlg.alignment = 'right';
//add drop-down
myDlg.DDgroup = myDlg.add('group');
myDlg.DDgroup.orientation = 'row';
myDlg.DDgroup.add('statictext', undefined, "Talen");
myDlg.DDgroup.DD = myDlg.DDgroup.add('dropdownlist', undefined, undefined, {items:myLanguages})
myDlg.DDgroup.DD.selection = 7;
myDlg.closeBtn = myDlg.add('button', undefined, 'OK');

// add button functions
myDlg.closeBtn.onClick = function() 
{ this.parent.close();
}
result = myDlg.show();
alert(myDlg.DDgroup.DD.selection);

for (i=0;i<myDoc.paragraphStyles.length;i++){
	try{
	myDoc.paragraphStyles[i].appliedLanguage = app.languagesWithVendors.item(myDlg.DDgroup.DD.selection.index);
	}catch(e){}
	}

for (k=0;k<myDoc.characterStyles.length;k++){
	try{
	myDoc.characterStyles[k].appliedLanguage = app.languagesWithVendors.item(myDlg.DDgroup.DD.selection.index);
	}catch(e){}
	}