How To Run If And Else Block Of Code Alternatively When Page Refresh C# Web App?

I am trying to implement some logics, but for that I have to use logic which I am not getting. How would I run an if condition and else condition alternative time when the page refreshes.

What would开发者_JAVA技巧 be the logic hopes for your suggestions?

my code is below,

var activeColor = '#ff0000';
var inactiveColor = '#0000FF';  
var points = [  
   new GLatLng(24.85229, 67.01703),  
   new GLatLng(24.914463, 67.0965958),  
   new GLatLng(24.86588, 67.06089),  
new GLatLng(24.9726753, 67.06638),
new GLatLng(24.840023, 67.24285),
new GLatLng(24.85229, 67.01703)
];  
var polyline = new GPolyline(points, '#ff0000', 5, 0.7);  
    GEvent.addListener(polyline, 'click', function() {
           var color = inactiveColor;
           inactiveColor = activeColor;
           activeColor = color;
           polyline.setStrokeStyle({ color: activeColor }); 
        });   
map.addOverlay(polyline);     
                              }
                            }
function reFresh() {
  location.reload(true) 
}
window.setInterval('reFresh()',20000);

How to change poly line color alternatively red and blue when page refresh how can we use if else condition here ??

hopes for your suggestions..

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Depending upon your actual usage, either a session variable or a value kept in a control.