nzBool function
function nzBool(val, def_val) {
var ret_val = val;
if (typeof def_val == "undefined" || def_val === null || def_val.length === 0) {
def_val = false;
}
if (typeof(val) == "undefined" || val === null || val.length === 0)
ret_val = def_val;
else if (typeof(val) == 'number')
ret_val = val == 1;
else if (typeof(val) == 'string')
ret_val = val == '1' || val == 'true';
else if (typeof(val) == 'boolean')
ret_val = val;
else
ret_val = def_val;
return ret_val;
}