Changing Levels through Scripts

How do you make a script that will change the level when i destory an item? and count how many remaining and count down to 0?

Regarding the first question: just use Application.LoadLevel() to change level in your game. The second one is not clear, sorry.

i m writing a pseudo code hereā€¦assuming that when enemy is killed you want to increase up the levelā€¦
int level=0;
int lastlevel=10;

if(enemy==null)
{
level++;
if(level==lastlevel)
{
//we reached the last level
}
currentlevel=level;
remaininglevel=lastlevel-currentlevel;
}