str = str.replace(/[()]/g,'')

str = str.slice(1,-1);

var a = "(23,45)";
a = a.replace("(","").replace(")","")

str = str.split("(").split(")").join();

str = str.substr(1, str.length-2);

"(23,45)".replace("(","").replace(")","")

var s = "(23,45)";
alert(s.replace(/[^0-9,]+/g,''))