Try adding a condition before concatenation. Use my code instead of this part:
document.getElementById("InsertRecordemailstosend").value = x1+" "+x2+" "+x3+" "+x4+" "+x5+" "+x6+" "+x7+" "+x8+" "+x9+" "+x10+" "+x11+" "+x12+" "+x13+" "+x14+" "+x15+" "+x16+" "+x17+" "+x18+" "+x19+" "+x20;
if (document.getElementById("cbParamVirtual1").checked==true)
{
document.getElementById("InsertRecordemailstosend").value = x1+" "+x2+" "+x3+" "+x4+" "+x5+" "+x6+" "+x7+" "+x8+" "+x9+" "+x10+" "+x11+" "+x12+" "+x13+" "+x14+" "+x15+" "+x16+" "+x17+" "+x18+" "+x19+" "+x20;
}
else{
document.getElementById("InsertRecordemailstosend").value = x12+" "+x13+" "+x14+" "+x15+" "+x16+" "+x17+" "+x18+" "+x19+" "+x20;
}