Jquery nefunguje v IE 7

$(document).ready(function(){
	
	$('#calculator').submit(function(e) {

		register3();
		e.preventDefault();
		
	});
	
});

function error3(act,txt)
{                                                               $
	hideshow3('calc-error',act);
	if(txt) $('#calc-error').html(txt);
}
function register3()
{
	hideshow3('vysledek',1);
	error3(0);
	
	$.ajax({
		type: "POST",
		url: "http://fyb.cz/module/security/zkontroluj_calc.php",
		data: $('#calculator').serialize(),
		dataType: "json",
		success: function(msg){
			
			if(parseInt(msg.status)==1)
			{
			
      $.ajax({
  type: 'POST',
  url: 'http://fyb.cz/module/security/spocitej.php',
  data: $('#calculator').serialize(),
  dataType: 'json',
  success: function(msg){ error3(1,msg.txt); }
});

				
			}
			if(parseInt(msg.status)==3)
			{
				window.location=msg.txt;
			}
						if(parseInt(msg.status)==2)
			{
				error3(1,msg.txt);
			}
			else if(parseInt(msg.status)==0)
			{
				error3(1,msg.txt);
			}
			
			hideshow3('vysledek',0);
		}
	});

}


function hideshow3(el,act)
{
	if(act) $('#'+el).css('visibility','visible');
	else $('#'+el).css('visibility','hidden');
}