I have one jquery method and i used call that method on click of a button .
So in that code i have one line \" $(\"#loadingMessage\").css(\'padding-top\',\'6%\');
        
use .one for once and use click for others.check below
  <script>
    $(document).ready(function() {
    $('#SearchButton').one('click', function() {
         $("#loadingMessage").css('padding-top','6%'); //I want this line execute only once, i mean first time
    });    
$('#SearchButton').click(function() {                 
         $(".spinner").css('visibility','hidden');
         loaderStart();
         document.getElementById('loadinggif3').style.display = "block";
         $("#loadinggif3").show();
         $(".col-sm-9").css('visibility','hidden');
          var str = $('#SearchText').val();
          str = str.trim();
         if(str=="") return false;
        });
  } ); 
       </script>  
quick and 'dirty' solution:
$.first_time = true;
$('#SearchButton').click(function() {                 
    if($.first_time == true) $("#loadingMessage").css('padding-top','6%');
    $.first_time = false;
});
some explanation: you need a global jQuery variable here ($.first_time in this example), so that it's still known inside the anonymous function of the click event.
you can use bolean in all languages.
in jquery:
var isFirst = true;
if(isFirst){  
$("#loadingMessage").css('padding-top','6%');  
isFirst=false;  
}