>Can I use it to check if a Object exist?
>Will this blow if the object do not exist?
>

>if vartype(thisform.oIntraData)="O"
>   ...

No. VARTYPE should only be used to check the type of a variable or property that you KNOW exists. It's shines in use for checking parameter types for functions with flexible parameter schemes. It should NOT be used to test for the existence of an object, a property, or really for that matter a variable. The VFP team has expressed repeatedly that VARTYPE is not a replacement for TYPE(), and should not be used indiscriminantly. They changed its behavior after its initial release to make it more friendly to unknown variables, but I don't think that they should have- it makes its use even more confusing.