PHP Session is not set using php & EXTJS

[Kanuck]

When I call a php file using Ajax, I do this : \[code\]function logIntoApp(){ Ext.Ajax.request({ url:'php/login.php', params:{ action:'login', email:Ext.getCmp('userLogin').getValue(), motDePasse:Ext.getCmp('passwordLogin').getValue() }, method:'GET', success:function(result, request){ //Ext.MessageBox.alert('Success', ); if(result.responseText == 'admin'){ //Ext.MessageBox.alert('Alert', result.responseText); window.location.replace("administration.php"); } else if(result.responseText == 'pro'){ //Ext.MessageBox.alert('Alert', result.responseText); window.location.replace("proAdministration.php"); } else{ Ext.MessageBox.alert('Alert', result.responseText);//'Email ou mot de passe incorrect!'); } }, failure:function(result, request){ Ext.MessageBox.alert('Failed', 'Erreur de chargement de donn