How to add markers on esri map with co-ordinates?

[VanithaV]

Hi All,
How to add markers to map with co-ordinates. I saved the extent in database along with X,Y co-ordinates after finding the location .While coming back to application i dont know how to add markers with co-oidinates.

var s = "";
          s = "XMin: " + ext.xmin +
       " YMin: " + ext.ymin +
       " XMax: " + ext.xmax +
       " YMax: " + ext.ymax;
          var spatialref = ext.spatialReference.wkid;
       document.getElementById('extent').value = s; 

function showCoordinates(evt) {
        //get mapPoint from event
        var mp = evt.mapPoint;
        //display mouse coordinatesLabel1
        dojo.byId("Label1").innerHTML = mp.x + ", " + mp.y;
      
    }

Anyone pls help to setExtent .

Thanks