function prepni(mrs)
  {
	
	if (mrs == "line1"){
						document.getElementById('line1').style.height = 'auto';
						document.getElementById('line1').style.visibility = 'visible';
							document.getElementById('line1').style.display = 'block';
						
		document.getElementById('line2').style.height = 0;
		document.getElementById('line2').style.display = 'none';

		} 
	
	if (mrs == "line2"){
					document.getElementById('line2').style.height = 'auto';
						document.getElementById('line2').style.visibility = 'visible';
							document.getElementById('line2').style.display = 'block';
						
		document.getElementById('line1').style.height = 0;
		document.getElementById('line1').style.display = 'none';

		} 
	
	}