Error using different .dat files

So i have a simple linear program written in my .mod file. However, i want to use different input parameters (+10%, +20% etc…) for each run. The .dat files are all identical except the changed parameters. I used an example from this forum and added the main block into my .mod (see below) to solve these instances, however i am getting an error that .datfiles is not available. I also tried to put it into a separate mod, but still without success. I would appreciate any help.

{string} datFiles={“+10% N.dat”,”+20% N.dat”};
main{
var src = new IloOplModelSource(“Fall 2_NP.mod”);
var cplex = new IloCplex();
var def = new IloOplModelDefinition(src);
    for(var datFile in thisOplModel.datFiles){
        var opl = new IloOplModel(def, cplex);    
        var data = new IloOplDataSource(datFile);
        opl.addDataSource(data);
        var details=opl.dataElements;
        opl.generate();
        if(cplex.solve()){
        writeln(“Gesamtkosten =” + cplex.getObjValue());}
        else{
            writeln(“No Solution”);}
}}