LCD Display Controlled By Button

I want make arduino code which is Ohm’s law kit. When I press button SuisVolt, LCD will display “Voltage Increase” and “Resistance Decrease”.

When I press button “SuisResis”, LCD will display “voltage decrease” and “Resistance Increase”.

the problem is, the display is sometimes is not true which is when I press SuisVolt, LCD display Resistance increase and Voltage decrease.

i hope you can help me

#include <LiquidCrystal.h>
int SuisVolt = 8; 
const int SuisResis = 9;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2); 
int SVoltState = 0;
int SResistState = 0;

void setup() { 
lcd.begin(16,2);
lcd.noDisplay();

// Set the button pin as an input.
pinMode(SuisVolt, INPUT);
pinMode(SuisResis, INPUT);
}
void loop() { 
SVoltState  = digitalRead(SuisVolt);
if (SVoltState  == HIGH)
{

lcd.clear();
lcd.display();
lcd.setCursor(0, 0);
lcd.print("Voltage Increase");
lcd.setCursor(0, 1);
lcd.print("Resistance Decrease");
delay(5000);
lcd.noDisplay();
}

//////////////////////////////  Resistor switch
SResistState = digitalRead(SuisResis);
if (SResistState == HIGH)
{

lcd.clear();
lcd.display();
lcd.setCursor(0, 0);
lcd.print("Voltage Decrease ");
lcd.setCursor(0, 1);
lcd.print("Resistance Increase");
delay(5000);
lcd.noDisplay();

}
}