[flexcoders] s:Group arrange component on the same center

[isa_loyer]

I use a s:Group to place my component in my form. I'd like all form item have 
the same horizontal align inside the group. I try to use horizontalcenter with 
value 0 but it doesn't work. So I don't know how to do and I hope you can help 
me to solve that.

<s:Group width="100%" resizeMode="noScale" verticalCenter="0" 
horizontalCenter="0">


                        <s:FormItem label="Naissance" tabIndex="5" 
x="{cbQualite.x}" id="fiNaissance">
                            <mx:DateField id="dfNaissance" width="100" 
editable="true" 
                                          formatString="DD/MM/YYYY" 
yearNavigationEnabled="true"
                                          />
                        </s:FormItem>
                        <s:RadioButton id="rbFem" label="Féminin" 
group="{rbsex}" tabIndex="7" 
                                       x="{fiNaissance.x + 
fiNaissance.width+5}" 
                                       />

                        <s:RadioButton id="rbMas" label="Masculin" 
group="{rbsex}" tabIndex="6" x="{rbFem.width + rbFem.x + 5}" y="{fiNaissance.y 
+(fiNaissance.height)/2}"/>
                        <s:DropDownList id="cbDossier2" 
dataProvider="{DP_PAT_DOS1}" width="118" height="22" tabIndex="8" 
x="{cbDossier1.x}"/>
                        <s:FormItem label="" tabIndex="9" x="{fiDossier1.x}" >
                            <s:TextInput id="fDossier2" width="90" 
paddingRight="5" text="@{objectPatient.paDossier2}" />
                        </s:FormItem>

                    </s:Group>