Setting a table cell's style?

[tailz]

Can anyone tell me why this bit of code just doesnt work please?

function showtab(show,count){
	
for(c=1;c<count+1;c++){
    if(show==c){
      document.getElementById('tabcell' + c).style='tabselected';
    }else{
      document.getElementById('tabcell' + c).style='tabunselected';
    }
  } 
}

All i'm trying to do is change the style of a cell when it gets clicked, the event fires but vstudio blows up on me.

any ideas?