Livecycle over/underflow error

I cannot seem to get past this error.  I have looked at the forums and still am getting either a script syntax error or the aritmetic error, depending on which way I change the script

Here is my script: (FormCalc)

if(NumericField1 ne 0 & HasValue(NumericField1)) then (NumericField1*NumericField12)elsenullendif

I am trying to multiply 2 fields and then all the multiplied fields are totaled - very simple "spreadsheet" function.  Can anyone tell me what I am doing wrong??

Thank you!!

MelissaP509