if(GETPOST("button_removefilter_x")||GETPOST("button_removefilter.x")||GETPOST("button_removefilter"))// Both test are required to be compatible with all browsers
if(GETPOST("button_removefilter_x")||GETPOST("button_removefilter.x")||GETPOST("button_removefilter"))// All tests are required to be compatible with all browsers