[Tugindia] doubts on tables

[#NAZIMUDEEN NAVEEN#]

Hi all, 
 
I am in the process of writing my first tex document and i am encountering some problems with the use of 
tables. Listing them below.
 
1)  While using the tabular environment i specified one column to be left justified by giving the 'l' option in the 
 column options. I wanted to centralise one of the cells of the table belonging to that column. I tried \centering , but that didn't work
 
2) I have used the setspace package to make the linespacing doubleline for the document. Inside the table i wanted to have some cells to be of single spacing. So i used a parbox, inside which \singlespacing was used. But then in the pdf output {using pdflatex}, the lines inside the parbox stood out separate from the rest of the row of the table. this inspite of the fact that i used the 't' option for the position. This problem did not occur when \singlespacing was not used ( but then the linespacing was double).
 
3) in a particular case i have a cell that has three other cells to its right, which means the left cell is of thickness 3 times to that of the right one. This i created by using tabular environment, and using cline{2-2} twice so that the right column had three rows, while the left had only one.I wanted to centralise the text { both veritcally as well as horizontally } in the left cell.  How can i do that?
 
This being my first query on the net if it is lengthy and the style of posting is not apt for a mailing list post
do bear with me. I should improve with time.
 
Thankyou
Naveen