STRING* g_str = " ";

...
...

function f_check_str(STRING* l_str)
{
   switch(l_str[1])
   {
        case 'a':
        { ..... }
        break;
    } 
}

....
....

str_cpy(g_str, "filos");
f_check_str(g_str);

...
...

STRING* tempStr = "#999";

function checkStr(STRING* str){
	// get amount of characters in the string:
	var char_amount = str_len(str);
	// init for loop:
	var i = 0;
	// run for loop, throw all characters:
	for(i = 0; i < char_amount; i ++){
		// get the character number here:
		var char_id = str_getchr(str, i);
		// run the switch statement to find the proper char:
		switch(char_id){
			// if we find (a) character:
			case 97: {
				// found [a] character:
				printf("Found [a] Character!");
				break;
			}		
			default:{
				break;
			}
		}
	}
}

void main(){
	checkStr("Blah");
}

//------------------------------------------------------------------------------------------
//------------------------------ function f_check_for_invalid_chars
function f_check_for_invalid_chars(STRING** l_array_str)
{
	int l_i = 0;
	int l_temp_1_int;
	int l_temp_2_int;
	
	STRING* l_temp_1_str = " ";
	char l_chr = ' ';
	
	bool l_while_stop_bool;
	
	l_temp_1_str = l_array_str[1];
	l_temp_2_int = str_len(l_temp_1_str);
	
	l_i = 1;
	l_while_stop_bool = false;
	
	while ( (l_i <= l_temp_2_int ) && (l_while_stop_bool == false) )
	{
		l_temp_1_int = 0;
		l_chr = str_getchr(l_temp_1_str, l_i);
		switch( l_chr )
		{
			case 'Q':
			case 'W':
			case 'E':
			case 'R':
			case 'T':
			case 'Y':
			case 'U':
			case 'I':
			case 'O':
			case 'P':
				
			case 'A':
			case 'S':
			case 'D':
			case 'F':
			case 'G':
			case 'H':
			case 'J':
			case 'K':
			case 'L':
				
			case 'Z':
			case 'X':
			case 'C':
			case 'V':
			case 'B':
			case 'N':
			case 'M':
			
			case 'q':
			case 'w':
			case 'e':
			case 'r':
			case 't':
			case 'y':
			case 'u':
			case 'i':
			case 'o':
			case 'p':
			
			case 'a':
			case 's':
			case 'd':
			case 'f':
			case 'g':
			case 'h':
			case 'j':
			case 'k':
			case 'l':
			
			case 'z':
			case 'x':
			case 'c':
			case 'v':
			case 'b':
			case 'n':
			case 'm':

			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
			case '0':
			{
				l_temp_1_int = 1;
			}
			break;
		}
		if (l_temp_1_int == 1)
		{
			l_i++;
		}
		else
		{
			l_while_stop_bool = true;
		}
		
	}
	
	if (l_while_stop_bool == true)
	{
		printf("Invalid Name");
		return -2;
	}
	else
	{
		printf("Name was saved");
		return 1;
	}
}

if ((l_chr >= 'A' && l_chr <= 'Z') || (l_chr >= 'a' && l_chr <= 'z') || (l_chr >= '0' && l_chr <= '9'))
    l_temp_1_int = 1;

//------------------------------------------------------------------------------------------
//------------------------------ function f_check_for_invalid_chars
function f_check_for_invalid_chars(STRING** l_array_str)
{
	int l_i = 0;
	int l_temp_1_int;
	int l_temp_2_int;
	
	STRING* l_temp_1_str = " ";
	char l_chr = ' ';
	
	bool l_while_stop_bool;
	
	l_temp_1_str = l_array_str[1];
	l_temp_2_int = str_len(l_temp_1_str);
	
	l_i = 1;
	l_while_stop_bool = false;
	
	while ( (l_i <= l_temp_2_int ) && (l_while_stop_bool == false) )
	{
		l_temp_1_int = 0;
		l_chr = str_getchr(l_temp_1_str, l_i);
		
                if (  (l_chr >= 'A' && l_chr <= 'Z') || 
                      (l_chr >= 'a' && l_chr <= 'z') || 
                      (l_chr >= '0' && l_chr <= '9')  )
                {
                    l_temp_1_int = 1;
                }

		if (l_temp_1_int == 1)
		{
			l_i++;
		}
		else
		{
			l_while_stop_bool = true;
		}
		
	}
	
	if (l_while_stop_bool == true)
	{
		printf("Invalid Name");
		return -2;
	}
	else
	{
		printf("Name was saved");
		return 1;
	}
}

while ( (l_i <= l_temp_2_int ) && (l_while_stop_bool == false) )
{
	l_temp_1_int = 0;
	l_chr = str_getchr(l_temp_1_str, l_i);
	
	if ((l_chr >= 'A' && l_chr <= 'Z') || 
	    (l_chr >= 'a' && l_chr <= 'z') || 
	    (l_chr >= '0' && l_chr <= '9')  )
	{
		l_i++;
	} else {
		l_while_stop_bool = true;
	}
}