In VBScript, string literals are surrounded by double quotes ( "). Here is what your first example shows:
Msgbox "This is myName" ' This works fine
, , , VBScript , . :
Msgbox "This is "myName"" ' This gives an error
^ ' because it prematurely terminates the string here
' and doesn't know what to do with the trailing "
, -. , , VBScript , " -". , escape- VBScript . :
Msgbox "This is ""myName""" 'This works fine
(\) escape-. . , VBScript escape, , :
Msgbox "This is \"myName\"" ' doesn't work in VBScript; example only
, :
Const Quote = """"
' ... later in the code ...
Msgbox "This is " & Quote & "myName" & Quote