[JS CS3] How to select Selection Tool

The following script gives the distance between two parallel guides and places that distance on the clipboard. For whatever reason I always end up with the Text Tool as the active tool.

var arrGuides = app.selection;
var docUnits = findDocUnits();
selectOnlyGuides();
switch(arrGuides.length){
        case 0:
        alert("Please select two parallel guides. \r\rYou did not select any.");
        break;
        case 1:
        alert("Please select two parallel guides. \r\rYou selected only one.");
        case 2:
        twoGuidesSelected();
        break;
        default:
        alert("Please select only two parallel guides. \r\rYou selected three or more.");
        break;
        }//end switch
arrGuides[0].select();    
arrGuides[1].select(SelectionOptions.ADD_TO);
//******FUNCTIONS************        
function findDocUnits(){
    if(app.activeDocument.viewPreferences.horizontalMeasurementUnits !=app.activeDocument.viewPreferences.verticalMeasurementUnits){
        alert("The vertical and horizontal units must both be either inches or picas. Please check the Preferences and set them the same.");
        exit();
        }//end  if
    else{
    var currentUnits = "";
    switch(app.activeDocument.viewPreferences.horizontalMeasurementUnits){
        case MeasurementUnits.INCHES:
        case MeasurementUnits.INCHES_DECIMAL:
        currentUnits = "inches";
        break;
        case MeasurementUnits.PICAS:
        currentUnits = "picas";
        break;
        default:
        alert("Your document should be set in only inches or picas. Please check the Preferences.");
        break;
        }//end switch
    }//end else
return currentUnits;
}//end function findDocUnits
function selectOnlyGuides(){
try{
    for(var i = 0; i< arrGuides.length; i++){
        if(arrGuides.constructor.name != "Guide"){
            var alert1="Please select two parallel guides and no other elements.";
            alert(alert1);
            exit();
        }//end try
            }//end if constructor.name
    }//end for 
catch(e){
    alert(alert1);
    }//end catch
}//end function selectOnlyGuides
function twoGuidesSelected(){
    //testing to see if perpendicular guides have been selected by user.
    try{
     if(arrGuides.length==2&&(arrGuides[0].orientation==HorizontalOrVertical.vertical&&arrGuides[1].orientation==HorizontalOrVertical.horizontal)||(arrGuides[1].orientation==HorizontalOrVertical.vertical&&arrGuides[0].orientation==HorizontalOrVertical.horizontal)){
        alert("Please select two parallel guides. \r\rYou selected two perpendicular ones.");
        }//end  if; test for perpendicular guides
    //testing if only horizontal or vertical guides have been selected. If yes, tell difference.
     if(arrGuides.length==2&&(arrGuides[0].orientation==HorizontalOrVertical.vertical&&arrGuides[1].orientation==HorizontalOrVertical.vertical)||(arrGuides[0].orientation==HorizontalOrVertical.horizontal&&arrGuides[1].orientation==HorizontalOrVertical.horizontal)){
        var deltaDistance = Math.abs((arrGuides[0].location)-(arrGuides[1].location)).toFixed(4);
        alert("The distance between the two guides is: "+deltaDistance+" "+docUnits+".\r\rThis figure is now on your clipboard if you want to paste it.");
        var numToCopy = deltaDistance;
        copyNum(numToCopy);
    }//end if; test for parallel guides.
}//end try
catch (e){//do nothing
    }//end catch
return arrGuides;
}//end function twoGuidesSelected
function copyNum(numToCopy){
var framePropRecord = {contents:numToCopy.toString()}
var myTextFrame = app.activeDocument.textFrames.add(framePropRecord);
myTextFrame.parentStory.texts[0].select();
app.copy();
myTextFrame.select();
myTextFrame.remove();
    }//end function numToCopy