Hi, Hans,,,,
'=' which means assigning a value to the field in the if statement..
You must use '==' or '==='.
form1.areaCalc1.Checkbox1::enter - (Javascript, client)
if (this.rawValue == 1){
xfa.resolveNode("NumericField1[2]").rawValue = 1;
} else {
xfa.resolveNode("NumericField1[2]").rawValue =0;
}
S,Candy.