// Create an XML to UI dialog box using the XML definition in the skew.xml file
var skewDlg = fl.getDocumentDOM().xmlPanel( fl.configURI + "Commands/skew.xml" ); 

// Place the values of xskew and yskew from the dialog box into local variables.
// Note that we cast (convert) the return value of skewDlg["xSkew"] to a number before assigning
// it to xSkew because the skewSelection method takes numbers as parameters.
var xSkew = Number(skewDlg.xSkew);
var ySkew = Number(skewDlg.ySkew);
var edge = skewDlg.edge;

if (skewDlg.dismiss == "accept") {

    // Place the values of xSkew and ySkew from the dialog box 
    // into local variables. The code casts (converts) the values from the 
    // dialog box to a number before assigning them to the local variables
    // because the skewSelection() method takes numbers for 
    // the xSkew and ySkew parameters.
    var xSkew = Number(skewDlg.xSkew);
    var ySkew = Number(skewDlg.ySkew);
    var edge    = skewDlg.edge;

    // check for valid input because sending 0 or undefined to
    // skewSelection() will cause the object to disappear.
    var inputIsValid = true;
    if (xSkew == 0 || isNaN(xSkew)) {
        inputIsValid = false;
    }
    if (ySkew == 0 || isNaN(ySkew)) {
        inputIsValid = false;
    }

    // Call skewSelection() to carry out the resizing command.
    if (inputIsValid ) {
        fl.getDocumentDOM().skewSelection(xSkew, ySkew, edge); 
    }
}