Apply character format using ExtendScript

function applyCharFmt (textRange, name, doc) {
    
    var charFmt, prop;
    
    // See if the character format exists.
    charFmt = doc.GetNamedCharFmt (name);
    if (charFmt.ObjectValid () === 1) {
        doc.SetTextProps (textRange, charFmt.GetProps ());
    }
    else { 
        // If not, just apply the name so that the text
        // will update when you import formts from a template.
        prop = new PropVal ();
        prop.propIdent.num = Constants.FP_CharTag;
        prop.propVal.valType = Constants.FT_String;
        prop.propVal.sval = name;
        doc.SetTextPropVal (textRange, prop);
    }
}