function tabactive( num){
	  tab1 = document.getElementById('tab_1');
	  tab2 = document.getElementById('tab_2');
	  c1 = document.getElementById('c_1');
	  c2 = document.getElementById('c_2');
	  if( num == 1){		
		tab1.className = 'tabberactive';
		tab2.className = '';
		c1.className = 'tabbertab'
		c2.className = 'tabbertab tabbertabhide';
	  }else{
	    tab1.className = '';
		tab2.className = 'tabberactive';
		c1.className = 'tabbertab tabbertabhide'
		c2.className = 'tabbertab';
	  }
	}