Running a Javacript if Another Script Returns True

I have a web form where I'd to like combine 2 different javascripts where the second runs only if the first returns true (out of true or false)  the first one is activated by

onSubmit="return checkSubmit()"

and runs the following script:

function checkSubmit()
{      
      if(frmCOShipping.AlreadyPosted.value=="NO")
      {                        
            frmCOShipping.AlreadyPosted.value="YES"
            return true;
      }
      else
      {
            return false;
      }      
}


The Second is activated by

onSubmit="runPrintJob(this)"

and runs the following script

function runPrintJob() {

  var shell = new ActiveXObject("WScript.shell");
  shell.run("S:/Scripts/PrintCatadyneSerialNumberLabel.bat "+frmCOShipping.Item.value+" "+frmCOShipping.Serial.value);
}


Right now,

onsubmit="if(checkSubmit() == true) {runPrintJob(this)}">

Runs the second as long as the first returns either true of false, how do i change it to run runPrintJob only if the first one does not return a false on frmCOShipping.AlreadyPosted?