The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value

This is procedure function whitout troubble

SET DATEFORMAT ymd;

ALTER PROCEDURE XSPS_EVENTS_SHIPPERS 'SMEDIT','2011-07-01' ,'2011-07-31'

@CPNYID AS VARCHAR(15),

@FECHAINI AS VARCHAR(10),

@FECHAFIN AS VARCHAR(10)

AS

/*

*/

DECLARE @SQL VARCHAR(400)

SET @SQL = 'SELECT * FROM '

SET @SQL = @SQL + RTRIM(@CPNYID) +'.DBO.XVR_EVENTS_SHIPPERS '

SET @SQL = @SQL + 'WHERE EventTime BETWEEN '''+ @FECHAINI+''' AND ''' +@FECHAFIN+''' Order by EventTime asc'

print @SQL

EXEC (@SQL)