Error flag question

In this case, if the first statement fails, and then the second statement succeeds, would the error flag carry through the second call and still be set when I test it?

ExecShell "open" "http://nsis.sf.net/"
ExecShell "open" "$INSTDIR\blah.txt"
${If} ${Errors}
DetailPrint "Failed to open blah.txt"
${EndIf}


Or do I need to do something more like this to ensure the erro flag is cleared?:

ExecShell "open" "http://nsis.sf.net/"
${If} ${Errors} ${EndIf}
ExecShell "open" "$INSTDIR\blah.txt"
${If} ${Errors}
DetailPrint "Failed to open blah.txt"
${EndIf}

It will carry on until it's cleared by ClearErrors or IfErrors.

Thanks again