fixed #910: when create new android project, not delete existing directory

create-android-project.bat

@@ -23,8 +23,9 @@ set _NDKROOT=d:\programe\android\ndk\android-ndk-r6b
 if not exist "%_NDKROOT%" echo Couldn't find ndk at "%_NDKROOT%" & pause & exit 6
 
 :: create android project
-set /P _PACKAGEPATH=Please enter your package path:
+set /P _PACKAGEPATH=Please enter your package path. For example: org.cocos2dx.example:
 set /P _PROJECTNAME=Please enter your project name:
+if exist "%CD%\%_PROJECTNAME%" echo "%_PROJECTNAME%" exists, please use another name & pause & exit 7
 echo "Now cocos2d-x suppurts Android 2.1-update1, 2.2, 2.3 & 3.0"
 echo "Other versions have not tested."
 call "%_ANDROIDTOOLS%\android.bat" list targets

create-android-project.sh

@@ -59,6 +59,12 @@ create_android_project(){
     echo "input your project name:"
     read PROJECT_NAME
     PROJECT_DIR=`pwd`/$PROJECT_NAME
+    
+    # check if PROJECT_DIR is exist
+    if [ -d $PROJECT_DIR ]; then
+        echo "$PROJECT_DIR is exist, please use another name"
+        exit
+    fi
 
     $ANDROID_SDK_ROOT_LOCAL/tools/android create project -n $PROJECT_NAME -t $TARGET_ID -k $PACKAGE_PATH -a $PROJECT_NAME -p $PROJECT_DIR
 }