completed clickCell(x,y) method to change value of cell by clicking it

src/backend/Simulator.java

@@ -157,6 +157,16 @@ public class Simulator extends Thread {
 	 */
 	public void clickCell(int x, int y) {
 		//TODO : complete method
+		//if clickActionFlag = true then create an agent
+		//else if flag = false then change value of cell
+		if(clickActionFlag) {
+			
+		}else {
+			if(getCell(x, y)==0) {
+				setCell(x, y, 1);
+			}else {setCell(x, y, 0);}
+		}
+		
 	}
 	
 	/**