//Gets transform nodes
string $nodes[] = `ls -selection`;
for ($node in $nodes)

{
//Gets shape nodes
string $shapes[] = `listRelatives -shapes $node`;


//Checks if shape is Double Sided
if (getAttr ($shapes[0] + ".doubleSided") == 1)
{
setAttr ($shapes[0] + ".doubleSided") (0);
setAttr ($shapes[0] + ".opposite") (1);
}
else
{
setAttr ($shapes[0] + ".doubleSided") (1);
setAttr ($shapes[0] + ".opposite") (0);
}


}