Please let me know how to check if an XML tag is present or not, using QTP.

for example,
in my script , i need to check if the tag <siteCLLI> is present in the given xml. so i have used the following code
If Child_Tag.ItemByName("site").ChildElements().ItemB yName("siteCLLI").Exist Then
SiteCLLI= Child_Tag.ItemByName("site").ChildElements().ItemB yName("siteCLLI").value
End If

but i get a syntax error. am i using the right format?