left side of frame to left page margin and right side of frame to right page margin

Hi,

below code may help you,

var myDoc = app.activeDocument;
myDoc.documentPreferences.facingPages = false;  
myDoc.viewPreferences.horizontalMeasurementUnits = MeasurementUnits.points;
myDoc.viewPreferences.verticalMeasurementUnits = MeasurementUnits.points;
var width = myDoc.documentPreferences.pageWidth;
var height = myDoc.documentPreferences.pageHeight;
for(var p=0; p<myDoc.pages.length; p++)
{
    for(var i =0;i<myDoc.pages
.textFrames.length;i++)  
    {  
        myPage = app.activeWindow.activePage;
        var myLeftMargin = myPage.marginPreferences.left;
        var myRightMargin = myPage.marginPreferences.right;
        var liveArea = width-myLeftMargin-myRightMargin;
        var myFrame = myDoc.pages
.textFrames;

        var gBounds = myFrame.geometricBounds;
        var myTextFrameWidth = gBounds[3]-gBounds[1];
        myFrame.select();
        if(gBounds[1]<(liveArea/2))
        {
            myFrame.move([myFrame.parentPage.marginPreferences.left, gBounds[0]]);  
        }  
        else  
        {  
            myFrame.move([(width-myRightMargin-myTextFrameWidth), gBounds[0]]);  
        }  
    }
}  
myDoc.documentPreferences.facingPages = true;  

Vandy