>In a label click method I wrote:
>
>*************************************************************
> STORE this.Caption TO cDia
>
>= MESSAGEBOX(cDia) ** it show the caption, OK
>*************************************************************
>
>However I as have many labels I decide to create a method in form,
>instead of repeating the method to each label
>
>*********************************************
>**method gereral
>STORE this.Caption TO cDia
>
>= MESSAGEBOX(cDia)
>***************************************************
>
>From each label click I call the method
>
>thisform.general
>
>However it returns blank value

In this case 'THIS' would refer to a form, not to a label.

You can instead do

thisform.General(this) && Label's click

>**method gereral
lparameters toLabel
STORE toLabel.Caption TO cDia
 
= MESSAGEBOX(cDia)