arduino call if analog input voltage change

hello!

I have a question, does it code work:

#include <SoftwareSerial.h>
SoftwareSerial SIM900(7, 8); 
void setup() {

  Serial.begin(9600);
   SIM900.begin(19200);               
  SIM900power();  
  delay(20000);  
}

void SIM900power()

{
  digitalWrite(9, HIGH);
  delay(1000);
  digitalWrite(9, LOW);
  delay(5000);
}
 
void callSomeone()
{
  SIM900.println("ATD + +123xxxxxx;"); 
  delay(100);
  SIM900.println();
  delay(30000);            
  SIM900.println("ATH");  
}
 
void loop() {

  int sensorValue = analogRead(A0);
  float voltage = sensorValue * (5.0 / 1023.0);
  if (float voltage => 0)
  {
  callSomeone();
  SIM900power();   
  do {} while (1); 
}
  

}

Answer: It doesn't compile, so no, it doesn't work.

Please remember to use code tags when posting your code.

i add all code now is this work?