actions required of eligible shareholders

hi
can any one explain to me what does it mean by below, it is in the letter to eligible shareholders, under "actions required of eligible shareholders"

"you may do nothing, if you choose to do nothing with your entitlement, while you continue to hold the same number of shares, your interest in the company will be diluted and you will receive no value for your entitlement?

can any one explain a bit more on above...i dont really undestand especially the second parts..."while you continue to hold the same number of shares, your interest in the company will be diluted"

thanks a lot