fixes

2-ui/2-events/01-introduction-browser-events/04-move-ball-field/solution.md

@@ -22,7 +22,7 @@ Then the ball will be positioned relatively to the field:
 }
 ```
 
-Next we need to assign the correct `ball.style.position.left/top`. They contain field-relative coordinates now.
+Next we need to assign the correct `ball.style.left/top`. They contain field-relative coordinates now.
 
 Here's the picture:
 
@@ -36,7 +36,7 @@ To get field-relative `left` coordinate of the click, we can substract the field
 let left = event.clientX - fieldCoords.left - field.clientLeft;
 ```
 
-Normally, `ball.style.position.left` means the "left edge of the element" (the ball). So if we assign that `left`, then the ball edge, not center, would be under the mouse cursor.
+Normally, `ball.style.left` means the "left edge of the element" (the ball). So if we assign that `left`, then the ball edge, not center, would be under the mouse cursor.
 
 We need to move the ball half-width left and half-height up to make it center.