example's error queue

Hi everybody, Could someone solve any trouble I've had with MikTex?.Well I'm getting start with MikTex, especially with PsTricks and I tried the following code snippet: \usepackage{pstcol}\begin{pspicture}(o,o)(2,2)\showgrid     \psline[linewidth=1pt,linecolor=gray]{<->}(0.5,0)(0,1)(1,1.5)(1.5,1)(.5,.5)\end{pspicture} However when I compile the associated file to this code snippet I get the following error queue: \usepackage before \documentclass. \usepackage{Environment pspicture undefined. \begin{pspicture}Missing \begin{document}. \begin{pspicture}(Undefined control sequence \begin{pspicture}(0,0)(2,2)\showgridUndefined control sequence \psline\begin{document ended by \end{pspicture}. end{pspicture}Emergency stop I wonder if I must add more code to the previous code snippet, since in th
 e error queue appears "\usepackage before \documentclass" and "Missing \begin{document}, but anyway  other errors appear which in my opinion don't make sense. I need some help, please!!!  		 	   		  
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