Fix typos

Author: ahocevar

lib/OpenLayers/Control/Graticule.js

@@ -157,7 +157,7 @@ OpenLayers.Control.Graticule = OpenLayers.Class(OpenLayers.Control, {
 
     /**
      * Property: projectionCenterLonLat
-     * {OpenLayers.LonLat} The center of the projection's validty extent.
+     * {OpenLayers.LonLat} The center of the projection's validity extent.
      */
     projectionCenterLonLat: null,
 
@@ -407,7 +407,7 @@ OpenLayers.Control.Graticule = OpenLayers.Class(OpenLayers.Control, {
         var centerLonLat = center.clone().transform(
             this.projection, this.epsg4326Projection);
         // If centerLonLat could not be transformed (e.g. [0, 0] in polar
-        // prjections), we shift the center a bit to get a result.
+        // projections), we shift the center a bit to get a result.
         if (isNaN(centerLonLat.lon) || isNaN(centerLonLat.lat)) {
             centerLonLat = center.add(0.000000001, 0.000000001).transform(
                 this.projection, this.epsg4326Projection);