If element is present on the mid of the two rows
if ( mat [ i_low ] [ j_mid ] == x ) document . write ( " " + i_low + " " + j_mid + " " ) ; else if ( mat [ i_low + 1 ] [ j_mid ] == x ) document . write ( " " + ( i_low + 1 ) + " " + j_mid + " " ) ;