more questions regarding modelsim and matlab simulink

hello everybody..


i'm trying to make feedback from modelsim to simulink component and to pass the value to my modelsim component irrespective to time (with respect to a non-time variable).. So I used an embedded matlab function component from simulink that works based upon input flag coming from modelsim component.. at this point i 've alot of errors

* there is a variable that is passed from workspace to the embedded component, it carries a string representing the video name.. to do so it should be timed and to avoid that i defined it as a global variable but it does'nt work also..

* also i'm not able to use either aviinfo() or mmreader() within embeded component

* within embeded component i'm randomizing a value using randint() to avoid being absolete i used randi
i got this error "Function 'randi' implicitly resolved in the MATLAB workspace. Implicit evaluation in MATLAB is not supported. Please declare this function extrinsic using eml.extrinsic('randi'), or call it using feval."

* beside that i'm having these errors
-->Coder Error: Errors occurred during parsing of Embedded MATLAB function 'Embedded MATLAB
-->InterfaceError :Embedded MATLAB Interface Error: Errors occurred during parsing of Embedded MATLAB function 'Embedded MATLAB

* plus this warning
-->Chart Embedded
MATLAB Function #18 has signals with underspecified type, size, and/or complexity.

* ONE MORE QUESTION plzz
for any used variable within this block should i define it as persistant first or what
as whenever i use a variable e.g. x_col = abs(round(x-(p_w/2))); got an error message asking me to declare it first

any help plzzzz

thanks