Changing Line Weight in Microstation 2004

Hello,

I'm want to change line thickness and I looked at these 2 articles

http://communities.bentley.com/products/programming/microstation_programming/f/343173/t/83313

communities.bentley.com/.../126376

but neither one has worked for me. Below is the code snippet that I have for changing line thickness

MSElement	tmpElem;
    MSElementDescr elmD;
    
    Dpoint3d lsPointss[2] = { {0, 0, 0},{10000,1000,0}};
    DPoint3d	dir = { 0, 0, 1 };
    
    mdlLine_create(&oElm, NULL, lsPointss);
    mdlElmdscr_new(&elmD, NULL, &oElm);
    elmD.h.dgnModelRef = ACTIVEMODEL;
    if(mdlLinkage_addThicknessToDescr(&elmD, 4.0, &dir, FALSE)==SUCCESS){
        mdlElmdscr_addByModelRef(&elmD,MASTERFILE);
    }

The mdlLinkage_addThicknessToDescr does not return SUCCESS. If I remove the IF condition, it adds the line without changes to thickness.

I searched in MDL Programmer's guide for this version of Microstation but there is just little information about this.

Description

Extracts the

thickness

value from the linkage of the specified element.

Required Header

<mslinkge.fdf>

How can I change weight for a line or linestring?

Regards,

Mohammad