Thread: crashing code

Why doesn't this code work? Is it because I have to allocate memory for char* tool_tip_text and how would I do that?

I've tried allocating memory using this, but it doesn't help either.
button->tool_tip_text = malloc(sizeof(char) * strlen(text)+1)

Code:

typedef struct {
   char* tool_tip_text;
}BUTTON;

int create_button(BUTTON* button, char* text)
{
   printf("%d",strlen(text));
   strcpy(button->tool_tip_text,text);
   return 0;
}

create_button(&my_button[0],"New Level");

After including the proper header file that code does actually fixes this problem.

I have one more question. Why doesn't this error checking work, unless I merge these two lines?

button->tool_tip_text = malloc(sizeof(char) * (strlen(text)+1) );
if(button->tool_tip_text == NULL)
return -1;

button->tool_tip_text = malloc(sizeof(char) * (strlen(text)+1) );
if(button->tool_tip_text == NULL)
return -1;

if((button->tool_tip_text = malloc(sizeof(char) * strlen(text)+1)) == NULL)
return -1;

Out these two samples of code the second one does what I want it to do. Why couldn't first line of code work?