char *str_replace(char * t1, char * t2, char * t6) {
    	char*t4;
    	char*t5=malloc(0);

        	while(strstr(t6,t1)){
        		t4=strstr(t6,t1);
        		strncpy(t5+strlen(t5),t6,t4-t6);
        		strcat(t5,t2);
        		t4+=strlen(t1);
        		t6=t4;
        	}

      return strcat(t5,t4);
}