Since you have a y50 Touch, replacing your touch panel is going to be quite a headache- not to mention going to cost quite a bit. You probably only broke the touch digitizer and the main LCD unit is probably intact, but as the two are glued together- you're going to have to replace the entire thing.
If you want to preserve your touchscreen functionality, refer to this guide: http://download.lenovo.com/consumer/mobiles_pub/lenovo_y40_50_series_hmm.pdf
pg.74 on how to replace your touch panel.
And you can buy a replacement panel at this website: http://www.usspareparts.com/lenovo-y5070-touch-display-screen-panel-p-41213.html which is the stock touch screen or you can buy a Samsung LTN156KL01 providing you can find someone that supplies it.
If you don't care about your touch functionality, you can buy any of the displays Vivian mentioned above- but you have to also buy the LCD Bezel and LCD non-touch cable for your laptop- you can get that off usspareparts.com as well- but it'll probably cost you a fair amount more even with a cheaper display unit. You have to refer to the same lenovo guide to remove the touch panel though and then install the non-touch panel by following the previous non-touch section in reverse.