Parent-Child Variable Issue

Hello,

I'm having problem to pass variable from a package to a another one.
I having 2 packages: the parent (parent.dtsx) use a Execute Package Task to execute the child package (child.dtsx).
In the parent package, I have a variable named var1 (data type String) with value=test
In my child package, I having a script task using the variable var1 to make a MsgBox (var1 is in readonly in the script):
MsgBox(CStr(Dts.Variables("var1").Value))

In this case, I having an error (cause the variable may no exist) but i can see the value of the variable in the MessageBox and the execute package task fail because of this error.

After I tried this solution: (Found in this Forum)
In the child package, I create the variable var1 (same type, no value). Then in the control flow, I right click on the background and select "package configurations".
I enable package configurations.
Then I add a new one. I change the configuration type to "parent package variable."
Then, in the specify configuration settings entry, I enter the name of the variable in the parent package.
On the following screen, I select the "value" property of the variable created in this package (Child package). At last, I give the configuration a name and hit finish.

If I execute my parent package, the result is no value in the MessageBox.

I also tried the same thing (with the package configuration) to pass a a variable with the connection string from a package to the connection of an another one (I set the connection string of the connection) and it doesn't work.

What did I miss ?


Thanks in advance for your help.

Regards