function update_surface(action){
        var e = document.getElementById("selected_surface");
        var x = e.options[e.selectedIndex].value;
        glviewer.removeSurface(surf);
        switch (action){
            case 1:
                if (x == 'SAS')
                   protein.surface = $3Dmol.SurfaceType.SAS;
                else if (x == 'SES')
                    protein.surface = $3Dmol.SurfaceType.SES;
                else if (x == 'VDW')
                    protein.surface = $3Dmol.SurfaceType.VDW;
                break;
            case 2:
                protein.opacity = 0.70;
                break;
            case 3: 
                protein.opacity = 1;
                break;
            case 4:
                protein.min_isoval = -5;
                protein.max_isoval = 5;
                break;
            
            default:
                break;
        }
            set_color();
        }
/*update surface based on selected action 
    * 0 -  
    * 1 - change surface
    * 2 - set translucent
    * 3 - set opaque
    */
update surface based on selected action
0
1 - change surface
2 - set translucent
3 - set opaque
update surface based on selected action 0 1 - change surface 2 - set translucent 3 - set opaque
function update_surface(action){
        var e = document.getElementById("selected_surface");
        var x = e.options[e.selectedIndex].value;
        glviewer.removeSurface(surf);
        switch (action){
            case 1:
                if (x == 'SAS')
                   protein.surface = $3Dmol.SurfaceType.SAS;
                else if (x == 'SES')
                    protein.surface = $3Dmol.SurfaceType.SES;
                else if (x == 'VDW')
                    protein.surface = $3Dmol.SurfaceType.VDW;
                break;
            case 2:
                protein.opacity = 0.70;
                break;
            case 3: 
                protein.opacity = 1;
                break;
            case 4:
                protein.min_isoval = -5;
                protein.max_isoval = 5;
                break;
            default:
                break;
        }
            set_color();
        }
function update_surface ( action ) { var e = document . getElementById ( "selected_surface" ) ; var x = e . options [ e . selectedIndex ] . value ; glviewer . removeSurface ( surf ) ; switch ( action ) { case 1 : if ( x == 'SAS' ) protein . surface = $3Dmol . SurfaceType . SAS ; else if ( x == 'SES' ) protein . surface = $3Dmol . SurfaceType . SES ; else if ( x == 'VDW' ) protein . surface = $3Dmol . SurfaceType . VDW ; break ; case 2 : protein . opacity = 0.70 ; break ; case 3 : protein . opacity = 1 ; break ; case 4 : protein . min_isoval = - 5 ; protein . max_isoval = 5 ; break ; default : break ; } set_color ( ) ; }
update surface based on selected action
 0 
 1 - change surface
 2 - set translucent
 3 - set opaque
update surface based on selected action 0 1 - change surface 2 - set translucent 3 - set opaque