Capacitive Sensing Library being ignored by arduino UNO.

ok,here is what i have written now, realizing my mistake with writing the library name,now after i compile it there is an error in the
long value = CS_4_2.CapacitiveSensor(30); line,saying that invalid use of class CapacitiveSensor

i am sorry but i am new to this library.

#include <CapacitiveSensor.h>
CapacitiveSensor CS_4_2 = CapacitiveSensor(4,2); // 10 megohm resistor between pins 4 & 2
void setup()
{
  CS_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF); // turn off autocalibrate on channel 1
  Serial.begin(9600);
}
void loop()
{
  long start = millis();
  long value  = CS_4_2.CapacitiveSensor(30);
  Serial.println(value);
  delay(100);
}