issue with millis()

So i am trying to get my arduino to control a pump. I dont want the pump to go on and immediatly off when the float get activated and deactivated. Ideally i would like to have the pump turn on and stay on for 10seconds and then turn off and recheck the switch. but right now it is just turning the led on and not doing anything else. the led it is turning on is connected to pin 6, which will be replaced with a relay/pump.

int Pumpswitch = 7;
int LowResSwitch = 12;
unsigned long Timer;

void setup()
{
pinMode(LowResSwitch, INPUT);
pinMode(Pumpswitch, INPUT);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);
}

void loop()
{
{
if (digitalRead (7) == HIGH)
Timer= millis();
digitalWrite(6, HIGH);

if (millis()-Timer >= 10000){
digitalWrite(7, LOW);

}
else
{
digitalWrite(6,LOW);}

if (digitalRead(12) == HIGH)
{
digitalWrite(5, HIGH);
}
else
{
digitalWrite(5, LOW);
}

}}

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Code tags.

Use the auto-format tool, please, as well.

Looks like the problem is that you're repeatedly setting Timer = millis(), which consequently means that millis() - Timer a few lines later is always going to be 0. You should only be setting Timer once. You need a state variable or two to keep track of what code should and shouldn't be running, namely when the pump is off, and then when it is on.

int Pumpswitch = 7; 
int LowResSwitch = 12;
unsigned long Timer;

void setup()
{
  pinMode(LowResSwitch, INPUT);
  pinMode(Pumpswitch, INPUT);
  pinMode(6, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop()
{
  {
    if (digitalRead (7) == HIGH)
      Timer= millis();
    digitalWrite(6, HIGH);

    if (millis()-Timer >= 10000){
      digitalWrite(7, LOW); 

    }
    else
    {
      digitalWrite(6,LOW);
    }


    if (digitalRead(12) == HIGH)
    {
      digitalWrite(5, HIGH); 
    }
    else
    {
      digitalWrite(5, LOW);
    }

  }
}