obj = document.bee.elements["feet_conversion"];
obj.options.length = 0;
for(i=0; i<feet_units.length; i++)
obj.options[obj.options.length] = new Option(feet_units[i][2], i);
obj = document.bee.elements["pounds_conversor"];
obj.options.length = 0;
for(i=0;i<pounds_units.length;i++)
obj.options[obj.options.length] = new Option(pounds_units[i][1], i);
obj = document.bee.elements["sex_conversor"];
obj.options.length = 0;
for(i=0;i<sex.length;i++)
obj.options[obj.options.length] = new Option(sex[i][4], i);