how to get current application path in wpf

``` public XML() { this.InitializeComponent(); XmlDocument document_name = new XmlDocument(); XmlElement student = document_name.CreateElement("Student"); XmlElement name = document_name.CreateElement("Chandru"); student.AppendChild(name); document_name.AppendChild(student); XmlAttribute id = document_name.CreateAttribute("ID"); name.SetAttributeNode(id); id.Value = "sst5038"; XmlElement fname = document_name.CreateElement("FName"); fname.InnerText = "Anjappn"; name.AppendChild(fname); XmlElement mname = document_name.CreateElement("MName"); mname.InnerText = "Thaiyamuthu"; name.AppendChild(mname); document_name.AppendChild(student); document_name.Save(@"D:\student.xml"); } ``` with above code.I create one xml file as code behind in wpf and i save this file in my local disk D:\student.xml ``` document_name.Save(@"D:\student.xml"); ``` But i want to save this xml file (student.xml) in my project file which i am working now. what should i do for this. please help me...