odd problem - led turns on when hand is near

ok, took code digitalread reference entry , tried use turn on led using switch (just wanted try digitalread, know don't need use switch). got led connected pin 12 , switch connected pin 7. time led turns on when switch on , hand nearby (not touching, nearby, regardless if i'm grounded wriststrap or not). circuit switch doesn't have completed; can have 1 wire in pin 7 , other in air not touching anything; put hand nearby , led turns on.

its basic knowledge known electronics savvy people, clueless up. btw, have tried setting circuit/s ton of different ways (common ground, seperate ciruits, in series no ground, in series common ground, pull resistor, pull down resistor, etc.); weren't correct gave me same result , rest gave me none. below code.

code: [select]

int ledpin = 12; // led connected digital pin 12
int inpin = 7;   // switch connected digital pin 7
int val = 0;     // variable store read value

void setup()
{
 pinmode(ledpin, output);      // sets digital pin 12 output
 pinmode(inpin, input);      // sets digital pin 7 input
}

void loop()
{
 val = digitalread(inpin);   // read input pin
 digitalwrite(ledpin, val);    // sets led switch's value
}

i'd guess problem in circuit.  check out photo button example: http://arduino.cc/en/tutorial/button

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