[v0id]

You're using the assignment-operator, when you're comparing the user-input, with the options to choose. You need to use the compare-operator instead. To optimize the code, I would prefer to use a switch-statement, instead of if's (there by the way, should have been if...elseif...else).

#include <stdio.h>

/* This is just a little thing, to make our application nicer */
#define SEPARATOR "------------------------------------\n"

int main()
{
	int i, c, type;
	
	type = 0; /* We need to initialize the type-variable */
	
	/* There isn't a big difference on int's and char's, so we don't  */
	/* need to use the ASCII-code, we can just you the real character */
	while(type != 'q')
	{
		printf("ASCII character program\n\n");
		printf(" Input 1, 2, 3, or q\n");
		printf("  1: ASCII code -> CHAR\n");
		printf("  2: CHAR -> ASCII code\n");
		printf("  3: DISPLAY ASCII TABLE\n");
		printf("  q: End of this Program\n");
		printf(" >> ");
		
		/* I see in your if-statements, you're using the ASCII-codes, */
		/* that means, we've to scan the _character_ using %c         */
		scanf("%c", &type);
		
		/* Separator */
		printf("%s", SEPARATOR);
		
		/* Flush everything in STDIN, so it don't keep it, */
		/* until the switch                                */
		fflush(stdin);
		
		/* This is our switch-statement */
		switch(type)
		{
			/* If the user choose '1' */
			case '1':
				printf("ASCII code -> CHAR\n");
				printf(" Input ASCII code: ");
				scanf("%d", &c);
				printf("  Character for ASCII code %d is -> '%c'\n\n", c, c);
				break;
				
			/* If the user choose '2' */
			case '2':
				printf("CHAR -> ASCII code\n");
				printf(" Input CHAR: ");
				scanf("%c", &c);
				printf("  ASCII code for character '%c' is -> '%d'\n\n", c, c);
				break;
				
			/* If the user choose '3' */
			case '3':
				printf("ASCII code table for 1-127\n");
      			for(i = 1; i <= 127; i++)
    				printf("Character for ASCII code %d is -> '%c'\n", i, i);
				break;
			
			/* If the user choose non of above */
			default:
				printf("Invalid option, try again...\n");
		}
		
		/* We need to flush again, before next round */
		fflush(stdin);
		printf("%s", SEPARATOR);
	}
}

That's how I would do it. As you can see it's using a switch-statement instead of the if-statements. It's usually a good idea to use a switch-statement, if there's many options. But there isn't so many in this one, so we could had used if...elseif...else-statement.

By the way, which compiler are you using? I've never seen comments like this;

int var = 10; * This is a comment *

Like you're using in your code. It isn't standard C, so stop using it.

C:
/* COMMENT */

C++:
// COMMENT
/* COMMENT */