$(document).keydown(function(event){

switch(event.keyCode){

case 37:

if(moveLeft()){

generationOneNumber();

}

   break;

case 38:

if(moveUp()){

generationOneNumber();

}   

   break;

case 39:

if(moveRight()){

generationOneNumber();

}

   break;

case 40:

if(moveDown()){

generationOneNumber();

}

   break;

default:

   break;

}

})

function moveLeft(){

if(!canMoveLeft(board)){

return false;

}

else{

//move left

for(var i=0;i<4;i++){

for(var j=1;j<4;j++){

if(board[i][j]!=0){

for(var k=0;k<j;k++){

if(board[i][k]==0 && noBlockHorizen(i,k,j,board)){

//move 

showMoveAnimation(i,j,i,k);

board[i][k]=board[i][j];

board[i][j]=0;

continue;

}

else if(board[i][k]==board[i][j] && noBlockHorizen(i,k,j,board)){

//move 

showMoveAnimation(i,j,i,k);

//add

board[i][k]+=board[i][j];

board[i][j]=0;

continue;

}

}

}

}

}

setTimeout("updateBoardView()",200);

return true

}

}

function canMoveLeft(board){

for(var i=0;i<4;i++){

for(var j=1;j<4;j++){

if(board[i][j]!= 0){

if(board[i][j-1]==0 || board[i][j-1]==board[i][j]){

return true;

}

else {

return false;

}

}

}

}

}

function noBlockHorizen(row,rol1,rol2,board){

for(var l=rol1+1;l<rol2;l++){

if(board[row][l]!=0){

return false;

}

else{

return true;

}

}

}