How can I constrain x components between [-10,10] in this matlab code, on random selection?

function [xval] = simulated_annealing()
tic
for i= 0:3
    x(i+1)=floor(random('unif',-10,10));
end

xval=x(1)^2+x(2)^2+x(3)^2+x(4)^2;

disp (x);
t = 1 ;
bool =true;
while bool
    
   t=t*.9;
   disp (t);
  temp=true;
  count=0;
   while (temp && count<11) 
       count=count+1;
      %random selection from neighbors
      newx(1)= floor(random('unif',x(1)-1,x(1)+1));
      newx(2)= floor(random('unif',x(2)-1,x(2)+1));
      newx(3)=floor( random('unif',x(3)-1,x(3)+1));
      newx(4)= floor(random('unif',x(4)-1,x(4)+1));
      %evaluate new x value
      newxval=x(1)^2+x(2)^2+x(3)^2+x(4)^2;
      
      disp(x);
      disp(newx);
      delta = newxval- xval ;
      if delta<0
       x=newx;
       temp=false;
      else 
        p =exp(-delta/t);
         if p > 0.3
            x=newx;
            temp=false;
     
         end
      end
   
   end
   
   if count>11
       bool=false;
   end
   
   
end

toc
disp (toc);