Print Maximum number

Hey guys-

I'm having an issue with this program I wrote. It is supposed to have a user enter values and then output the maximum value of those values entered, using very basic C Programming. If only the sentinel value is entered, it will print out an error message. I have that working properly, but when I enter values, it outputs the maxmium, but when I enter the sentinel value (999), it outputs that as the maximum, which it shouldn't do. Any ideas? I'm probably just overlooking something very simple. I appreciate the help! Thanks!!

-----------------

Code:

...
while (temp != 999)
{               
   printf("Enter another value [enter 999 to stop]:\n");
   scanf("%f",&temp);
   counter == counter++; 

	if ( temp > max) 
	{
	max = temp;
	}
	else if ( temp < max)
	{
	temp = temp;
	}
}

if ( counter != 1 )
   {
   printf("The maximum is: %f\n", max);
   }
else
   {
   printf("No valid entires:\n");
   }
}

If the input is 999 then don't update the max value and don't output it.

Code:

while (temp != 999)
{               
   printf("Enter another temperature [enter 999 to stop]:\n");
   scanf("%f",&temp);
   if(temp!=999)
   {
      counter == counter++; 

	if ( temp > max) 
	{
	max = temp;
	}
	else if ( temp < max)
	{
	temp = temp;
	}
      printf("Temperature = %f\n", temp);
      printf("Counter = %d\n", counter);
      printf("Maximum = %f\n", max);
   }
}

Thanks! I figured it was just a stupid mistake. Appreciate it!

Can I suggest a number of changes?

Code:

#include <stdio.h>

int main() {
    float temp; 
    int counter = 0;
    float max;	

    printf("Enter a temperature [enter 999 to stop]:\n");
    scanf("%f", &temp);
    
    while (temp != 999) {
        counter++; 
        
        if (temp > max)  {
            max = temp;
        }
        
        printf("Temperature = %f\n", temp);
        printf("Counter = %d\n", counter);
        printf("Maximum = %f\n", max);
        
        printf("Enter a temperature [enter 999 to stop]:\n");
        scanf("%f", &temp);
    }

    if (counter > 1) {
        printf("The maximum temperature is: %f\n", max);
    } else {
        printf("No valid temperatures were entered\n");
    }
    return 0;
}

Edit: Formatting