css - javascript function not working when a new if statement added -

i have function stick nav sidebar top after scrolling.but when screen minimizes logo on top shortens , position of nav changes.so wrote 'if' function inside first 1 solve problem.now position correct nav side bar fixing on top while scrolling.can please me....the function below....

$(function() {        var stickyheadertop = $('#myscrollspy').offset().top;        var yy = document.getelementbyid("cor").clientheight;        $(window).scroll(function() {            if ($(window).scrolltop() > stickyheadertop) {                 $('#myscrollspy').css({                    position: 'fixed',                    top: '8px',                    left: '0px'                });                 $('#my').css({                    position: 'absolute',                    right: '0px'                });             } else {                setinterval(function() {                    if (yy < '490') {                         var yu = '500' - yy;                         $('#myscrollspy').css({                            position: 'absolute',                            top: ''                            700 '-yy',                            left: '0px'                        });                        $('#my').css({                            position: 'absolute',                            right: '0px'                        });                    }                }, 30);            }        });    }); 

you have syntax issues, have mentioned them in comments below.

              if (yy < 490) { //syntax issue here                        var yu = 500 - yy; //syntax issue here                         $('#myscrollspy').css({                            position: 'absolute',                            top: (700 - yy)+'px', //syntax issue here                            left: '0px'                        });                        $('#my').css({                            position: 'absolute',                            right: '0px'                        });                    } 

document.getelementbyid("cor").clientheight return int(number).

check element.clientheight

note: property round value integer. if need fractional value, use element.getboundingclientrect().