I am having a problem with the following code:

m.carloc = ThisForm.carousel + ;
           PADL(LTRIM(STR(ThisForm.bin, 2, 0)), 2, "0") + ;
           PADL(LTRIM(STR(ThisForm.shelf, 2, 0)), 2, "0") + ;
           ThisForm.loc   
              
lc_update = [carloc = ?m.carloc]
lc_item   = ThisForm.citem

*-- Update ICITEM table  	
lcSQL = [UPDATE icitem SET ] + lc_update + [ WHERE item = ] + lc_item  
lnRetVal = SQLEXEC(ln_connection, lcSQL) 

m.carloc is a character type variable and the carloc field in icitem is set as a character field. When the update is attempted AERROR() says that the problem is "Error converting data type varchar to numeric."

I don't understand why any conversion would be necessary and why numberic?

Thank you